51
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Mishra R, Hegner M. Effect of non-specific species competition from total RNA on the static mode hybridization response of nanomechanical assays of oligonucleotides. NANOTECHNOLOGY 2014; 25:225501. [PMID: 24807191 DOI: 10.1088/0957-4484/25/22/225501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate here the nanomechanical response of microcantilever sensors in real-time for detecting a range of ultra-low concentrations of oligonucleotides in a complex background of total cellular RNA extracts from cell lines without labeling or amplification. Cantilever sensor arrays were functionalized with probe single stranded DNA (ssDNA) and reference ssDNA to obtain a differential signal. They were then exposed to complementary target ssDNA strands that were spiked in a fragmented total cellular RNA background in biologically relevant concentrations so as to provide clinically significant analysis. We present a model for prediction of the sensor behavior in competitive backgrounds with parameters that are indicators of the change in nanomechanical response with variation in the target and background concentration. For nanomechanical assays to compete with current technologies it is essential to comprehend such responses with eventual impact on areas like understanding non-coding RNA pharmacokinetics, nucleic acid biomarker assays and miRNA quantification for disease monitoring and diagnosis to mention a few. Additionally, we also achieved a femtomolar sensitivity limit for online oligonucleotide detection in a non-competitive environment with these sensors.
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Affiliation(s)
- Rohit Mishra
- Centre for Research on Adaptive Nanostructures and Nanodevices, School of Physics, Trinity College, Dublin 2, Ireland
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52
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Grewal YS, Shiddiky MJ, Spadafora LJ, Cangelosi GA, Trau M. Nano-yeast–scFv probes on screen-printed gold electrodes for detection of Entamoeba histolytica antigens in a biological matrix. Biosens Bioelectron 2014; 55:417-22. [DOI: 10.1016/j.bios.2013.12.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/04/2013] [Accepted: 12/18/2013] [Indexed: 11/16/2022]
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53
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Wu S, Liu H, Liang XM, Wu X, Wang B, Zhang Q. Highly Sensitive Nanomechanical Immunosensor Using Half Antibody Fragments. Anal Chem 2014; 86:4271-7. [DOI: 10.1021/ac404065m] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shangquan Wu
- CAS
Key Laboratory of Mechanical Behavior and Design of Material, Department
of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Hong Liu
- Department
of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xin M. Liang
- CAS
Key Laboratory of Mechanical Behavior and Design of Material, Department
of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027, China
- Center
for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaoping Wu
- CAS
Key Laboratory of Mechanical Behavior and Design of Material, Department
of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Baomin Wang
- College
of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Qingchuan Zhang
- CAS
Key Laboratory of Mechanical Behavior and Design of Material, Department
of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027, China
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54
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Park J, Bang D, Jang K, Kim E, Haam S, Na S. Multimodal label-free detection and discrimination for small molecules using a nanoporous resonator. Nat Commun 2014; 5:3456. [DOI: 10.1038/ncomms4456] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 02/14/2014] [Indexed: 11/09/2022] Open
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55
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Mehrabani S, Maker AJ, Armani AM. Hybrid integrated label-free chemical and biological sensors. SENSORS (BASEL, SWITZERLAND) 2014; 14:5890-928. [PMID: 24675757 PMCID: PMC4029679 DOI: 10.3390/s140405890] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/10/2014] [Accepted: 03/14/2014] [Indexed: 12/13/2022]
Abstract
Label-free sensors based on electrical, mechanical and optical transduction methods have potential applications in numerous areas of society, ranging from healthcare to environmental monitoring. Initial research in the field focused on the development and optimization of various sensor platforms fabricated from a single material system, such as fiber-based optical sensors and silicon nanowire-based electrical sensors. However, more recent research efforts have explored designing sensors fabricated from multiple materials. For example, synthetic materials and/or biomaterials can also be added to the sensor to improve its response toward analytes of interest. By leveraging the properties of the different material systems, these hybrid sensing devices can have significantly improved performance over their single-material counterparts (better sensitivity, specificity, signal to noise, and/or detection limits). This review will briefly discuss some of the methods for creating these multi-material sensor platforms and the advances enabled by this design approach.
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Affiliation(s)
- Simin Mehrabani
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA.
| | - Ashley J Maker
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA.
| | - Andrea M Armani
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA.
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56
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Thakur G, Jiang K, Lee D, Prashanthi K, Kim S, Thundat T. Investigation of pH-induced protein conformation changes by nanomechanical deflection. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2109-2116. [PMID: 24512545 DOI: 10.1021/la403981t] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Broad-spectrum biosensing technologies examine sensor signals using biomarkers, such as proteins, DNA, antibodies, specific cells, and macromolecules, based on direct- or indirect-conformational changes. Here, we have investigated the pH-dependent conformational isomerization of human serum albumin (HSA) using microcantilevers as a sensing platform. Native and denatured proteins were immobilized on cantilever surfaces to understand the effect of pH on conformational changes of the protein with respect to the coupling ligand. Our results show that protonation and deprotonation of amino acid residues on proteins play a significant role in generating charge-induced cantilever deflection. Surface plasmon resonance (SPR) was employed as a complementary technique to validate the results.
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Affiliation(s)
- Garima Thakur
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada
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57
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Nanosensor dosimetry of mouse blood proteins after exposure to ionizing radiation. Sci Rep 2014; 3:2234. [PMID: 23868657 PMCID: PMC3715761 DOI: 10.1038/srep02234] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 07/01/2013] [Indexed: 01/15/2023] Open
Abstract
Giant magnetoresistive (GMR) nanosensors provide a novel approach for measuring protein concentrations in blood for medical diagnosis. Using an in vivo mouse radiation model, we developed protocols for measuring Flt3 ligand (Flt3lg) and serum amyloid A1 (Saa1) in small amounts of blood collected during the first week after X-ray exposures of sham, 0.1, 1, 2, 3, or 6 Gy. Flt3lg concentrations showed excellent dose discrimination at ≥ 1 Gy in the time window of 1 to 7 days after exposure except 1 Gy at day 7. Saa1 dose response was limited to the first two days after exposure. A multiplex assay with both proteins showed improved dose classification accuracy. Our magneto-nanosensor assay demonstrates the dose and time responses, low-dose sensitivity, small volume requirements, and rapid speed that have important advantages in radiation triage biodosimetry.
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58
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Cho H, Zook J, Banner T, Park SH, Min BH, Hasty KA, Pinkhassik E, Lindner E. Immobilization of fibrinogen antibody on self-assembled gold monolayers for immunosensor applications. Tissue Eng Regen Med 2014. [DOI: 10.1007/s13770-013-1119-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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59
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Borrebaeck CAK, Wingren C. High-throughput proteomics using antibody microarrays: an update. Expert Rev Mol Diagn 2014; 7:673-86. [PMID: 17892372 DOI: 10.1586/14737159.7.5.673] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Antibody-based microarrays are a rapidly emerging technology that has advanced from the first proof-of-concept studies to demanding serum protein profiling applications during recent years, displaying great promise within disease proteomics. Miniaturized micro- and nanoarrays can be fabricated with an almost infinite number of antibodies carrying the desired specificities. While consuming only minute amounts of reagents, multiplexed and ultrasensitive assays can be performed targeting high- as well as low-abundance analytes in complex nonfractionated proteomes. The microarray images generated can then be converted into protein expression profiles or protein atlases, revealing a detailed composition of the sample. The technology will provide unique opportunities for fields such as disease diagnostics, biomarker discovery, patient stratification, predicting disease recurrence and drug target discovery. This review describes an update of high-throughput proteomics, using antibody-based microarrays, focusing on key technological advances and novel applications that have emerged over the last 3 years.
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Affiliation(s)
- Carl A K Borrebaeck
- Lund University, Department of Immunotechnology & CREATE Health, BMC D13, SE-221 84 Lund, Sweden.
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60
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Maloney N, Lukacs G, Ball SL, Hegner M. Device for filamentous fungi growth monitoring using the multimodal frequency response of cantilevers. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:015003. [PMID: 24517802 DOI: 10.1063/1.4854655] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Filamentous fungi cause opportunistic infections in hospital patients. A fast assay to detect viable spores is of great interest. We present a device that is capable of monitoring fungi growth in real time via the dynamic operation of cantilevers in an array. The ability to detect minute frequency shifts for higher order flexural resonance modes is demonstrated using hydrogel functionalised cantilevers. The use of higher order resonance modes sees the sensor dependent mass responsivity enhanced by a factor of 13 in comparison to measurements utilizing the fundamental resonance mode only. As a proof of principle measurement, Aspergillus niger growth is monitored using the first two flexural resonance modes. The detection of single spore growth within 10 h is reported for the first time. The ability to detect and monitor the growth of single spores, within a small time frame, is advantageous in both clinical and industrial settings.
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Affiliation(s)
- N Maloney
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2, Ireland
| | - G Lukacs
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2, Ireland
| | - S L Ball
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2, Ireland
| | - M Hegner
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2, Ireland
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61
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Wu S, Nan T, Xue C, Cheng T, Liu H, Wang B, Zhang Q, Wu X. Mechanism and enhancement of the surface stress caused by a small-molecule antigen and antibody binding. Biosens Bioelectron 2013; 48:67-74. [DOI: 10.1016/j.bios.2013.03.086] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/25/2013] [Accepted: 03/30/2013] [Indexed: 10/27/2022]
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62
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Lab on a chip for in situ diagnosis: From blood to point of care. Biomed Eng Lett 2013; 3:59-66. [PMID: 32226641 PMCID: PMC7100328 DOI: 10.1007/s13534-013-0094-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 06/25/2013] [Indexed: 11/02/2022] Open
Abstract
As the point of care diagnosis devices are becoming ever more popular, this paper suggest a miniaturized testing device from a drop of blood to diagnosis of disease for the global healthcare. The minimal requirements for the POC blood-testing device are blood microsampling, blood separation, immunoassay, and detection and communication of the signals. The microsampling of the blood can be achieved by specialized needle, which can be connected to the microchip or analytical devices. The sampled blood is then separated using either a filter (weir or pillar type), or by the phenomena unique to microfluidic system. The separated blood should then go through sandwich, homogeneous non-competitive, or competitive immunoassay, which can effectively diagnose diverse diseases. Lastly, the device should detect and translate the immune-signals to readable, and clinically significant signals. The development of such device will play a great role for improving healthcare technology.
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63
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Huang YW, Wu CS, Chuang CK, Pang ST, Pan TM, Yang YS, Ko FH. Real-Time and Label-Free Detection of the Prostate-Specific Antigen in Human Serum by a Polycrystalline Silicon Nanowire Field-Effect Transistor Biosensor. Anal Chem 2013; 85:7912-8. [DOI: 10.1021/ac401610s] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Yu-Wen Huang
- Department of Materials Science
and Engineering, Chiao-Tung University,
Hsinchu 300, Taiwan
| | - Chung-Shu Wu
- Department of Materials Science
and Engineering, Chiao-Tung University,
Hsinchu 300, Taiwan
| | - Cheng-Keng Chuang
- Division
of Urology, Chang Gung Memorial Hospital, Taiyuan 333, Taiwan
| | - See-Tong Pang
- Division
of Urology, Chang Gung Memorial Hospital, Taiyuan 333, Taiwan
| | - Tung-Ming Pan
- Department
of Electronics Engineering, Chang Gung University, Taoyuan 333, Taiwan
| | - Yuh-Shyong Yang
- Department of Biological Science
and Technology, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Fu-Hsiang Ko
- Department of Materials Science
and Engineering, Chiao-Tung University,
Hsinchu 300, Taiwan
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64
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Sang S, Zhao Y, Zhang W, Li P, Hu J, Li G. Surface stress-based biosensors. Biosens Bioelectron 2013; 51:124-35. [PMID: 23948243 DOI: 10.1016/j.bios.2013.07.033] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 06/27/2013] [Accepted: 07/12/2013] [Indexed: 01/13/2023]
Abstract
Surface stress-based biosensors, as one kind of label-free biosensors, have attracted lots of attention in the process of information gathering and measurement for the biological, chemical and medical application with the development of technology and society. This kind of biosensors offers many advantages such as short response time (less than milliseconds) and a typical sensitivity at nanogram, picoliter, femtojoule and attomolar level. Furthermore, it simplifies sample preparation and testing procedures. In this work, progress made towards the use of surface stress-based biosensors for achieving better performance is critically reviewed, including our recent achievement, the optimally circular membrane-based biosensors and biosensor array. The further scientific and technological challenges in this field are also summarized. Critical remark and future steps towards the ultimate surface stress-based biosensors are addressed.
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Affiliation(s)
- Shengbo Sang
- MicroNano System Research Center, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China; Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China
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65
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Site-directed antibody immobilization techniques for immunosensors. Biosens Bioelectron 2013; 50:460-71. [PMID: 23911661 DOI: 10.1016/j.bios.2013.06.060] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 06/14/2013] [Accepted: 06/26/2013] [Indexed: 02/07/2023]
Abstract
Immunosensor sensitivity, regenerability, and stability directly depend on the type of antibodies used for the immunosensor design, quantity of immobilized molecules, remaining activity upon immobilization, and proper orientation on the sensing interface. Although sensor surfaces prepared with antibodies immobilized in a random manner yield satisfactory results, site-directed immobilization of the sensing molecules significantly improves the immunosensor sensitivity, especially when planar supports are employed. This review focuses on the three most conventional site-directed antibody immobilization techniques used in immunosensor design. One strategy of immobilizing antibodies on the sensor surface is via affinity interactions with a pre-formed layer of the Fc binding proteins, e.g., protein A, protein G, Fc region specific antibodies or various recombinant proteins. Another immobilization strategy is based on the use of chemically or genetically engineered antibody fragments that can be attached to the sensor surface covered in gold or self-assembled monolayer via the sulfhydryl groups present in the hinge region. The third most common strategy is antibody immobilization via an oxidized oligosaccharide moiety present in the Fc region of the antibody. The principles, advantages, applications, and arising problems of these most often applied immobilization techniques are reviewed.
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66
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Senveli SU, Tigli O. Biosensors in the small scale: methods and technology trends. IET Nanobiotechnol 2013; 7:7-21. [PMID: 23705288 DOI: 10.1049/iet-nbt.2012.0005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
This study presents a review on biosensors with an emphasis on recent developments in the field. A brief history accompanied by a detailed description of the biosensor concepts is followed by rising trends observed in contemporary micro- and nanoscale biosensors. Performance metrics to quantify and compare different detection mechanisms are presented. A comprehensive analysis on various types and subtypes of biosensors are given. The fields of interest within the scope of this review are label-free electrical, mechanical and optical biosensors as well as other emerging and popular technologies. Especially, the latter half of the last decade is reviewed for the types, methods and results of the most prominently researched detection mechanisms. Tables are provided for comparison of various competing technologies in the literature. The conclusion part summarises the noteworthy advantages and disadvantages of all biosensors reviewed in this study. Furthermore, future directions that the micro- and nanoscale biosensing technologies are expected to take are provided along with the immediate outlook.
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Affiliation(s)
- Sukru U Senveli
- Department of Electrical and Computer Engineering, University of Miami, Coral Gables, FL 33146, USA
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67
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Ngoepe M, Choonara YE, Tyagi C, Tomar LK, du Toit LC, Kumar P, Ndesendo VMK, Pillay V. Integration of biosensors and drug delivery technologies for early detection and chronic management of illness. SENSORS (BASEL, SWITZERLAND) 2013; 13:7680-713. [PMID: 23771157 PMCID: PMC3715220 DOI: 10.3390/s130607680] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 05/21/2013] [Accepted: 06/07/2013] [Indexed: 11/17/2022]
Abstract
Recent advances in biosensor design and sensing efficacy need to be amalgamated with research in responsive drug delivery systems for building superior health or illness regimes and ensuring good patient compliance. A variety of illnesses require continuous monitoring in order to have efficient illness intervention. Physicochemical changes in the body can signify the occurrence of an illness before it manifests. Even with the usage of sensors that allow diagnosis and prognosis of the illness, medical intervention still has its downfalls. Late detection of illness can reduce the efficacy of therapeutics. Furthermore, the conventional modes of treatment can cause side-effects such as tissue damage (chemotherapy and rhabdomyolysis) and induce other forms of illness (hepatotoxicity). The use of drug delivery systems enables the lowering of side-effects with subsequent improvement in patient compliance. Chronic illnesses require continuous monitoring and medical intervention for efficient treatment to be achieved. Therefore, designing a responsive system that will reciprocate to the physicochemical changes may offer superior therapeutic activity. In this respect, integration of biosensors and drug delivery is a proficient approach and requires designing an implantable system that has a closed loop system. This offers regulation of the changes by means of releasing a therapeutic agent whenever illness biomarkers prevail. Proper selection of biomarkers is vital as this is key for diagnosis and a stimulation factor for responsive drug delivery. By detecting an illness before it manifests by means of biomarkers levels, therapeutic dosing would relate to the severity of such changes. In this review various biosensors and drug delivery systems are discussed in order to assess the challenges and future perspectives of integrating biosensors and drug delivery systems for detection and management of chronic illness.
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Affiliation(s)
- Mpho Ngoepe
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa; E-Mails: (M.N.); (Y.E.C.); (L.C.D.); (P.K.); (C.T.) (L.K.T.)
| | - Yahya E. Choonara
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa; E-Mails: (M.N.); (Y.E.C.); (L.C.D.); (P.K.); (C.T.) (L.K.T.)
| | - Charu Tyagi
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa; E-Mails: (M.N.); (Y.E.C.); (L.C.D.); (P.K.); (C.T.) (L.K.T.)
| | - Lomas Kumar Tomar
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa; E-Mails: (M.N.); (Y.E.C.); (L.C.D.); (P.K.); (C.T.) (L.K.T.)
| | - Lisa C. du Toit
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa; E-Mails: (M.N.); (Y.E.C.); (L.C.D.); (P.K.); (C.T.) (L.K.T.)
| | - Pradeep Kumar
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa; E-Mails: (M.N.); (Y.E.C.); (L.C.D.); (P.K.); (C.T.) (L.K.T.)
| | - Valence M. K. Ndesendo
- School of Pharmacy and Pharmaceutical Sciences, St. John's University of Tanzania, Dodoma, Tanzania; E-Mail:
| | - Viness Pillay
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa; E-Mails: (M.N.); (Y.E.C.); (L.C.D.); (P.K.); (C.T.) (L.K.T.)
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68
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A self-sensing piezoelectric microcantilever biosensor for detection of ultrasmall adsorbed masses: theory and experiments. SENSORS 2013; 13:6089-108. [PMID: 23666133 PMCID: PMC3690046 DOI: 10.3390/s130506089] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 05/04/2013] [Accepted: 05/06/2013] [Indexed: 11/16/2022]
Abstract
Detection of ultrasmall masses such as proteins and pathogens has been made possible as a result of advancements in nanotechnology. Development of label-free and highly sensitive biosensors has enabled the transduction of molecular recognition into detectable physical quantities. Microcantilever (MC)-based systems have played a widespread role in developing such biosensors. One of the most important drawbacks of all of the available biosensors is that they all come at a very high cost. Moreover, there are certain limitations in the measurement equipments attached to the biosensors which are mostly optical measurement systems. A unique self-sensing detection technique is proposed in this paper in order to address most of the limitations of the current measurement systems. A self-sensing bridge is used to excite piezoelectric MC-based sensor functioning in dynamic mode, which simultaneously measures the system's response through the self-induced voltage generated in the piezoelectric material. As a result, the need for bulky, expensive read-out equipment is eliminated. A comprehensive mathematical model is presented for the proposed self-sensing detection platform using distributed-parameters system modeling. An adaptation strategy is then implemented in the second part in order to compensate for the time-variation of piezoelectric properties which dynamically improves the behavior of the system. Finally, results are reported from an extensive experimental investigation carried out to prove the capability of the proposed platform. Experimental results verified the proposed mathematical modeling presented in the first part of the study with accuracy of 97.48%. Implementing the adaptation strategy increased the accuracy to 99.82%. These results proved the measurement capability of the proposed self-sensing strategy. It enables development of a cost-effective, sensitive and miniaturized mass sensing platform.
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69
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Carbon Nanotubes-Based Label-Free Affinity Sensors for Environmental Monitoring. Appl Biochem Biotechnol 2013; 170:1011-25. [DOI: 10.1007/s12010-013-0233-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 04/07/2013] [Indexed: 10/26/2022]
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70
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Zhang J, Lang HP, Battiston F, Backmann N, Huber F, Gerber C. Development of robust and standardized cantilever sensors based on biotin/NeutrAvidin coupling for antibody detection. SENSORS 2013; 13:5273-85. [PMID: 23604028 PMCID: PMC3673136 DOI: 10.3390/s130405273] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/10/2013] [Accepted: 04/15/2013] [Indexed: 11/23/2022]
Abstract
A cantilever-based protein biosensor has been developed providing a customizable multilayer platform for the detection of antibodies. It consists of a biotin-terminated PEG layer pre-functionalized on the gold-coated cantilever surface, onto which NeutrAvidin is adsorbed through biotin/NeutrAvidin specific binding. NeutrAvidin is used as a bridge layer between the biotin-coated surface and the biotinylated biomolecules, such as biotinylated bovine serum albumin (biotinylated BSA), forming a multilayer sensor for direct antibody capture. The cantilever biosensor has been successfully applied to the detection of mouse anti-BSA (m-IgG) and sheep anti-BSA(s-IgG) antibodies. As expected, the average differential surface stress signals of about 5.7 ± 0.8 × 10−3 N/m are very similar for BSA/m-IgG and BSA/s-IgG binding, i.e., they are independent of the origin of the antibody. A statistic evaluation of 112 response curves confirms that the multilayer protein cantilever biosensor shows high reproducibility. As a control test, a biotinylated maltose binding protein was used for detecting specificity of IgG, the result shows a signal of bBSA layer in response to antibody is 5.8 × 10−3 N/m compared to bMBP. The pre-functionalized biotin/PEG cantilever surface is found to show a long shelf-life of at least 40 days and retains its responsivity of above 70% of the signal when stored in PBS buffer at 4 °C. The protein cantilever biosensor represents a rapid, label-free, sensitive and reliable detection technique for a real-time protein assay.
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Affiliation(s)
- Jiayun Zhang
- Swiss Nano Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland; E-Mails: (H.P.L.); (N.B.); (F.H.); (C.G.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +41-61-267-3769; Fax: +41-61-267-3784
| | - Hans Peter Lang
- Swiss Nano Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland; E-Mails: (H.P.L.); (N.B.); (F.H.); (C.G.)
| | - Felice Battiston
- Concentris GmbH, Davidsbodenstrasse 63, 4056 Basel, Switzerland; E-Mail:
| | - Natalija Backmann
- Swiss Nano Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland; E-Mails: (H.P.L.); (N.B.); (F.H.); (C.G.)
| | - Francois Huber
- Swiss Nano Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland; E-Mails: (H.P.L.); (N.B.); (F.H.); (C.G.)
| | - Christoph Gerber
- Swiss Nano Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland; E-Mails: (H.P.L.); (N.B.); (F.H.); (C.G.)
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71
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Han KN, Li CA, Seong GH. Microfluidic chips for immunoassays. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2013; 6:119-41. [PMID: 23495732 DOI: 10.1146/annurev-anchem-062012-092616] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The use of microfluidic chips for immunoassays has been extensively explored in recent years. The combination of immunoassays and microfluidics affords a promising platform for multiple, sensitive, and automatic point-of-care (POC) diagnostics. In this review, we focus on the description of recent achievements in microfluidic chips for immunoassays categorized by their detection method. Following a brief introduction to the basic principles of each detection method, we examine current microfluidic immunosensor detection systems in detail. We also highlight interesting strategies for sensitive immunosensing configurations, multiplexed analysis, and POC diagnostics in microfluidic immunosensors.
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Affiliation(s)
- Kwi Nam Han
- Department of Bionanoengineering, Hanyang University, Ansan 426-791, South Korea.
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72
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Grewal YS, Shiddiky MJA, Gray SA, Weigel KM, Cangelosi GA, Trau M. Label-free electrochemical detection of an Entamoeba histolytica antigen using cell-free yeast-scFv probes. Chem Commun (Camb) 2013; 49:1551-3. [PMID: 23329132 PMCID: PMC3564640 DOI: 10.1039/c2cc38882k] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inexpensive, simple and quick detection of pathogen antigens in human samples is a key global health objective. Limiting factors include the cost and complexity of diagnostic tests that utilize antibody probes. Herein, we present a method for label-free electrochemical detection of a protein from the enteric pathogen Entamoeba histolytica using cell-free yeast-embedded antibody-like fragments (yeast-scFv) as novel affinity reagents.
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Affiliation(s)
- Yadveer S. Grewal
- Centre for Biomarker Research and Development, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia. Tel: +61-7-33464178. Fax: +61-7-33463973
| | - Muhammad J. A. Shiddiky
- Centre for Biomarker Research and Development, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia. Tel: +61-7-33464178. Fax: +61-7-33463973
| | - Sean A. Gray
- Seattle Biomedical Research Institute, Seattle, WA 98117, USA
| | - Kris M. Weigel
- Seattle Biomedical Research Institute, Seattle, WA 98117, USA
| | | | - Matt Trau
- Centre for Biomarker Research and Development, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia. Tel: +61-7-33464178. Fax: +61-7-33463973
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73
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Huber F, Lang HP, Backmann N, Rimoldi D, Gerber C. Direct detection of a BRAF mutation in total RNA from melanoma cells using cantilever arrays. NATURE NANOTECHNOLOGY 2013; 8:125-129. [PMID: 23377457 DOI: 10.1038/nnano.2012.263] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 12/18/2012] [Indexed: 05/27/2023]
Abstract
Malignant melanoma, the deadliest form of skin cancer, is characterized by a predominant mutation in the BRAF gene. Drugs that target tumours carrying this mutation have recently entered the clinic. Accordingly, patients are routinely screened for mutations in this gene to determine whether they can benefit from this type of treatment. The current gold standard for mutation screening uses real-time polymerase chain reaction and sequencing methods. Here we show that an assay based on microcantilever arrays can detect the mutation nanomechanically without amplification in total RNA samples isolated from melanoma cells. The assay is based on a BRAF-specific oligonucleotide probe. We detected mutant BRAF at a concentration of 500 pM in a 50-fold excess of the wild-type sequence. The method was able to distinguish melanoma cells carrying the mutation from wild-type cells using as little as 20 ng µl(-1) of RNA material, without prior PCR amplification and use of labels.
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Affiliation(s)
- F Huber
- Swiss Nano Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
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74
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Abstract
The discovery of naturally occurring, heavy-chain only antibodies in Camelidae, and their further development into small recombinant nanobodies, presents attractive alternatives in drug delivery and imaging. Easily expressed in microorganisms and amenable to engineering, nanobody derivatives are soluble, stable, versatile, and have unique refolding capacities, reduced aggregation tendencies, and high-target binding capabilities. This review outlines the current state of the art in nanobodies, focusing on their structural features and properties, production, technology, and the potential for modulating immune functions and for targeting tumors, toxins, and microbes.
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Affiliation(s)
- Christina G Siontorou
- Department of Industrial Management and Technology, University of Piraeus, Piraeus, Greece
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75
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Yoshikawa G, Akiyama T, Loizeau F, Shiba K, Gautsch S, Nakayama T, Vettiger P, de Rooij NF, Aono M. Two dimensional array of piezoresistive nanomechanical Membrane-type Surface Stress Sensor (MSS) with improved sensitivity. SENSORS 2012. [PMID: 23202237 PMCID: PMC3522990 DOI: 10.3390/s121115873] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present a new generation of piezoresistive nanomechanical Membrane-type Surface stress Sensor (MSS) chips, which consist of a two dimensional array of MSS on a single chip. The implementation of several optimization techniques in the design and microfabrication improved the piezoresistive sensitivity by 3~4 times compared to the first generation MSS chip, resulting in a sensitivity about ~100 times better than a standard cantilever-type sensor and a few times better than optical read-out methods in terms of experimental signal-to-noise ratio. Since the integrated piezoresistive read-out of the MSS can meet practical requirements, such as compactness and not requiring bulky and expensive peripheral devices, the MSS is a promising transducer for nanomechanical sensing in the rapidly growing application fields in medicine, biology, security, and the environment. Specifically, its system compactness due to the integrated piezoresistive sensing makes the MSS concept attractive for the instruments used in mobile applications. In addition, the MSS can operate in opaque liquids, such as blood, where optical read-out techniques cannot be applied.
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Affiliation(s)
- Genki Yoshikawa
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan; E-Mails: (K.S.); (T.N.); (M.A.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-29-860-4749; Fax: +81-29-860-4706
| | - Terunobu Akiyama
- Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel CH-2002, Switzerland; E-Mails: (T.A.); (F.L.); (S.G.); (P.V.); (N.F.R.)
| | - Frederic Loizeau
- Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel CH-2002, Switzerland; E-Mails: (T.A.); (F.L.); (S.G.); (P.V.); (N.F.R.)
| | - Kota Shiba
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan; E-Mails: (K.S.); (T.N.); (M.A.)
| | - Sebastian Gautsch
- Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel CH-2002, Switzerland; E-Mails: (T.A.); (F.L.); (S.G.); (P.V.); (N.F.R.)
| | - Tomonobu Nakayama
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan; E-Mails: (K.S.); (T.N.); (M.A.)
| | - Peter Vettiger
- Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel CH-2002, Switzerland; E-Mails: (T.A.); (F.L.); (S.G.); (P.V.); (N.F.R.)
| | - Nico F. de Rooij
- Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel CH-2002, Switzerland; E-Mails: (T.A.); (F.L.); (S.G.); (P.V.); (N.F.R.)
| | - Masakazu Aono
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan; E-Mails: (K.S.); (T.N.); (M.A.)
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76
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Shiddiky MJ, Kithva PH, Kozak D, Trau M. An electrochemical immunosensor to minimize the nonspecific adsorption and to improve sensitivity of protein assays in human serum. Biosens Bioelectron 2012; 38:132-7. [DOI: 10.1016/j.bios.2012.05.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 05/09/2012] [Accepted: 05/12/2012] [Indexed: 12/20/2022]
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77
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Park S, Hwang D, Chung J. Cotinine-conjugated aptamer/anti-cotinine antibody complexes as a novel affinity unit for use in biological assays. Exp Mol Med 2012; 44:554-61. [PMID: 22809871 PMCID: PMC3465749 DOI: 10.3858/emm.2012.44.9.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2012] [Indexed: 01/12/2023] Open
Abstract
Aptamers are synthetic, relatively short (e.g., 20-80 bases) RNA or ssDNA oligonucleotides that can bind targets with high affinity and specificity, similar to antibodies, because they can fold into unique, three-dimensional shapes. For use in various assays and experiments, aptamers have been conjugated with biotin or digoxigenin to form complexes with avidin or anti-digoxigenin antibodies, respectively. In this study, we developed a method to label the 5' ends of aptamers with cotinine, which allows formation of a stable complex with anti-cotinine antibodies for the purpose of providing another affinity unit for the application in biological assays using aptamers. To demonstrate the functionality of this affinity unit in biological assays, we utilized two well-known aptamers: AS1411, which binds nucleolin, and pegaptanib, which binds vascular endothelial growth factor. Cotinine-conjugated AS1411/ anti-cotinine antibody complexes were successfully applied to immunoblot, immunoprecipitation, and flow cytometric analyses, and cotinine-conjugated pegaptanib/ anti-cotinine antibody complexes were used successfully in enzyme immunoassays. Our results show that cotinine-conjugated aptamer/anti-cotinine antibody complexes are an effective alternative and complementary technique for aptamer use in multiple assays and experiments.
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Affiliation(s)
- Sunyoung Park
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 110-799, Korea
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78
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Kierny MR, Cunningham TD, Kay BK. Detection of biomarkers using recombinant antibodies coupled to nanostructured platforms. NANO REVIEWS 2012; 3:NANO-3-17240. [PMID: 22833780 PMCID: PMC3404449 DOI: 10.3402/nano.v3i0.17240] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 05/30/2012] [Accepted: 06/09/2012] [Indexed: 12/14/2022]
Abstract
The utility of biomarker detection in tomorrow's personalized health care field will mean early and accurate diagnosis of many types of human physiological conditions and diseases. In the search for biomarkers, recombinant affinity reagents can be generated to candidate proteins or post-translational modifications that differ qualitatively or quantitatively between normal and diseased tissues. The use of display technologies, such as phage-display, allows for manageable selection and optimization of affinity reagents for use in biomarker detection. Here we review the use of recombinant antibody fragments, such as scFvs and Fabs, which can be affinity-selected from phage-display libraries, to bind with both high specificity and affinity to biomarkers of cancer, such as Human Epidermal growth factor Receptor 2 (HER2) and Carcinoembryonic antigen (CEA). We discuss how these recombinant antibodies can be fabricated into nanostructures, such as carbon nanotubes, nanowires, and quantum dots, for the purpose of enhancing detection of biomarkers at low concentrations (pg/mL) within complex mixtures such as serum or tissue extracts. Other sensing technologies, which take advantage of 'Surface Enhanced Raman Scattering' (gold nanoshells), frequency changes in piezoelectric crystals (quartz crystal microbalance), or electrical current generation and sensing during electrochemical reactions (electrochemical detection), can effectively provide multiplexed platforms for detection of cancer and injury biomarkers. Such devices may soon replace the traditional time consuming ELISAs and Western blots, and deliver rapid, point-of-care diagnostics to market.
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Affiliation(s)
- Michael R Kierny
- Department of Biological Sciences, University of Illinois at Chicago (UIC), Chicago, IL, USA
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79
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Abstract
The alarming rise in drug-resistant hospital ‘superbugs’ and the associated increase in fatalities is driving the development of technologies to search for new antibiotics and improve disease diagnostics. One of the most successful drug targets is the bacterial cell wall, an evolutionary feature of virtually all prokaryotes and vital for their survival by providing mechanical strength. The recent discovery of bacterial cytoskeletal proteins analogous to the key force-bearing machinery in eukaryotes also provides new opportunities for drug discovery, but little is known about their mechanical role in bacteria. In the present short article, I review recent developments in the field of nanotechnology to investigate the mechanical mechanisms of action of potent antibiotics on cell wall and cytoskeletal targets with unprecedented spatial, temporal and force resolution and the development of a new generation of nanomechanical devices to detect pathogens for point-of-care diagnostics.
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80
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Abstract
Piezoelectric microcantilever sensors (PEMS) can be sensitive tools for the detection of proteins and cells in biological fluids. However, currently available PEMS can only be used a single time or must be completely stripped and refunctionalized prior to subsequent uses. Here we report the successful use of an alternative regeneration protocol employing high salt concentrations to remove the target, leaving the functional probe immobilized on the microcantilever surface. Our model system employed the extracellular domain (ECD) of recombinant human Epidermal Growth Factor Receptor (EGFR) as the probe and anti-human EGFR polyclonal antibodies as the target. We report that high concentrations of MgCl2 dissociated polyclonal antibodies specifically bound to EGFR ECD immobilized on the sensor surface without affecting its bioactivity. This simple regeneration protocol both minimized the time required to re-conjugate the probe and preserved the density of probe immobilized on PEMS surface, yielding identical biosensor sensitivity over a series of assays.
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81
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ZHANG HY, PAN HQ, ZHANG BL, TANG JL. Microcantilever Sensors for Chemical and Biological Applications in Liquid. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2012. [DOI: 10.1016/s1872-2040(11)60549-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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82
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Park J, Kim H, Blick RH. Quasi-dynamic mode of nanomembranes for time-of-flight mass spectrometry of proteins. NANOSCALE 2012; 4:2543-2548. [PMID: 22378023 DOI: 10.1039/c2nr11779g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mechanical resonators realized on the nano-scale by now offer applications in mass-sensing of biomolecules with extraordinary sensitivity. The general idea is that perfect mechanical biosensors should be of extremely small size to achieve zeptogram sensitivity in weighing single molecules similar to a balance. However, the small scale and long response time of weighing biomolecules with a cantilever restrict their usefulness as a high-throughput method. Commercial mass spectrometry (MS) such as electro-spray ionization (ESI)-MS and matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF)-MS are the gold standards to which nanomechanical resonators have to live up to. These two methods rely on the ionization and acceleration of biomolecules and the following ion detection after a mass selection step, such as time-of-flight (TOF). Hence, the spectrum is typically represented in m/z, i.e. the mass to ionization charge ratio. Here, we describe the feasibility and mass range of detection of a new mechanical approach for ion detection in time-of-flight mass spectrometry, the principle of which is that the impinging ion packets excite mechanical oscillations in a silicon nitride nanomembrane. These mechanical oscillations are henceforth detected via field emission of electrons from the nanomembrane. Ion detection is demonstrated in MALDI-TOF analysis over a broad range with angiotensin, bovine serum albumin (BSA), and an equimolar protein mixture of insulin, BSA, and immunoglobulin G (IgG). We find an unprecedented mass range of operation of the nanomembrane detector.
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Affiliation(s)
- Jonghoo Park
- Electrical and Computer Engineering, University of Wisconsin, Madison, WI 53706, USA
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83
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Punzet M, Baurecht D, Varga F, Karlic H, Heitzinger C. Determination of surface concentrations of individual molecule-layers used in nanoscale biosensors by in situ ATR-FTIR spectroscopy. NANOSCALE 2012; 4:2431-8. [PMID: 22399200 DOI: 10.1039/c2nr12038k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
For the development of nanowire sensors for chemical and medical detection purposes, the optimal functionalization of the surface is a mandatory component. Quantitative ATR-FTIR spectroscopy was used in situ to investigate the step-by-step layer formation of typical functionalization protocols and to determine the respective molecule surface concentrations. BSA, anti-TNF-α and anti-PSA antibodies were bound via 3-(trimethoxy)butylsilyl aldehyde linkers to silicon-oxide surfaces in order to investigate surface functionalization of nanowires. Maximum determined surface concentrations were 7.17 × 10(-13) mol cm(-2) for BSA, 1.7 × 10(-13) mol cm(-2) for anti-TNF-α antibody, 6.1 × 10(-13) mol cm(-2) for anti-PSA antibody, 3.88 × 10(-13) mol cm(-2) for TNF-α and 7.0 × 10(-13) mol cm(-2) for PSA. Furthermore we performed antibody-antigen binding experiments and determined the specific binding ratios. The maximum possible ratio of 2 was obtained at bulk concentrations of the antigen in the μg ml(-1) range for TNF-α and PSA.
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Affiliation(s)
- Manuel Punzet
- Institute of Biophysical Chemistry, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
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84
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Binding kinetics of grouper nervous necrosis viruses with functionalized antimicrobial peptides by nanomechanical detection. Biosens Bioelectron 2012; 31:116-23. [DOI: 10.1016/j.bios.2011.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 10/01/2011] [Accepted: 10/03/2011] [Indexed: 01/18/2023]
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85
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Park J, Nishida S, Lambert P, Kawakatsu H, Fujita H. High-resolution cantilever biosensor resonating at air-liquid in a microchannel. LAB ON A CHIP 2011; 11:4187-4193. [PMID: 22038280 DOI: 10.1039/c1lc20608g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have developed a highly mass-sensitive cantilever resonating at the interface of air and liquid. The cantilever is applicable as a biosensor by measuring its resonance frequency shift associated with the selective trapping of target molecules. One surface of the cantilever facing to the liquid is functionalized for label-free detection, while the opposite side is exposed to air to improve the resonance characteristics, such as the quality factor. The quality factor at resonance is 15, which is 50% higher than the same cantilever in liquid. The beam was excited through the photothermal effect of a power modulated laser and detected by laser Doppler velocimetry. Due to the proposed configuration, the signal-to-noise-ratio is 5.7 times larger than the completely submerged case. A micro-slit around the cantilever separates the air and liquid phases at a meniscus. We analyzed the cantilever motion including the meniscus membrane, and examined the effect of surface tension by applying various solutions. A slit width of 6 μm was found to give the best performance within the few prototypes. We measured the covalent immobilization of antibody molecules on a cantilever surface for three different concentrations: 20, 40, and 80 μg ml(-1). The kinetics measured by both resonance frequency shift of the cantilever and fluorescent intensity showed good agreement.
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Affiliation(s)
- Jungwook Park
- Center for International Research on Micronano Mechatronics (CIRMM), Institute of Industrial Science (IIS), the University of Tokyo, 4-6-1 Komaba Meguro, Tokyo, 153-8505, Japan.
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86
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Low-concentration mechanical biosensor based on a photonic crystal nanowire array. Nat Commun 2011; 2:578. [DOI: 10.1038/ncomms1587] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 11/03/2011] [Indexed: 11/08/2022] Open
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87
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Hu X, O’Connor IB, Wall JG. Antibody Immobilization on Solid Surfaces: Methods and Applications. BIOLOGICAL INTERACTIONS WITH SURFACE CHARGE IN BIOMATERIALS 2011. [DOI: 10.1039/9781849733366-00090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The correct immobilization of the antibody component is one of the most critical steps in the development of immunoassays, immunosensors and immunochromatography matrices. Advances in hybridoma technology and protein engineering have allowed traditional limitations of polyreactivity of antibody preparations, poor device stability and random orientation of binding pockets to be largely overcome, resulting in stable, sensitive, highly specific and enormously diverse immunoplatforms with applications in diagnostics, environmental monitoring, and food and public safety. In this Chapter we introduce antibody structure and antibody-derived fragments, describe the most common methods of their immobilization and discuss ‘traditional’ applications of immobilized antibodies such as enzyme immunoassays and immunoaffinity chromatography, as well as exciting emerging uses in immunosensors, microarrays and nanomedicine.
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Affiliation(s)
- X. Hu
- National University of Ireland, Galway, Microbiology and Network of Excellence in Functional Biomaterials University Road, Galway Ireland
- Dalian University, Medical School Dalian Development Zone, Dalian China
| | - I. B. O’Connor
- National University of Ireland, Galway, Microbiology and Network of Excellence in Functional Biomaterials University Road, Galway Ireland
| | - J. G. Wall
- National University of Ireland, Galway, Microbiology and Network of Excellence in Functional Biomaterials University Road, Galway Ireland
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88
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Conducting polymer nanowires-based label-free biosensors. Curr Opin Biotechnol 2011; 22:502-8. [DOI: 10.1016/j.copbio.2011.05.508] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 05/17/2011] [Accepted: 05/18/2011] [Indexed: 12/29/2022]
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89
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Timurdogan E, Alaca BE, Kavakli IH, Urey H. MEMS biosensor for detection of Hepatitis A and C viruses in serum. Biosens Bioelectron 2011; 28:189-94. [PMID: 21803562 DOI: 10.1016/j.bios.2011.07.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/27/2011] [Accepted: 07/09/2011] [Indexed: 10/18/2022]
Abstract
Resonant microcantilever arrays are developed for the purpose of label-free and real-time analyte monitoring and biomolecule detection. MEMS cantilevers made of electroplated nickel are functionalized with Hepatitis antibodies. Hepatitis A and C antigens at different concentrations are introduced in undiluted bovine serum. All preparation and measurement steps are carried out in the liquid within a specifically designed flowcell without ever drying the cantilevers throughout the experiment. Both actuation and sensing are done remotely and therefore the MEMS cantilevers have no electrical connections, allowing for easily disposable sensor chips. Actuation is achieved using an electromagnet and the interferometric optical sensing is achieved using laser illumination and embedded diffraction gratings at the tip of each cantilever. Resonant frequency of the cantilevers in dynamic motion is monitored using a self-sustaining closed-loop control circuit and a frequency counter. Specificity is demonstrated by detecting both Hepatitis A and Hepatitis C antigens and their negative controls. This is the first report of Hepatitis antigen detection by resonant cantilevers exposed to undiluted serum. A dynamic range in excess of 1000 and with a minimum detectable concentration limit of 0.1ng/ml (1.66pM) is achieved for both Hepatitis A and C. This result is comparable to labeled detection methods such as ELISA.
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Affiliation(s)
- Erman Timurdogan
- Koc University, Electrical and Electronics Engineering, Rumeli Feneri Yolu, 34450 Sariyer, Istanbul, Turkey
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90
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Wang HQ, Wu Z, Tang LJ, Yu RQ, Jiang JH. Fluorescence protection assay: a novel homogeneous assay platform toward development of aptamer sensors for protein detection. Nucleic Acids Res 2011; 39:e122. [PMID: 21742759 PMCID: PMC3185441 DOI: 10.1093/nar/gkr559] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Development of novel aptamer sensor strategies for rapid and selective assays of protein biomarkers plays crucial roles in proteomics and clinical diagnostics. Herein, we have developed a novel aptamer sensor strategy for homogeneous detection of protein targets based on fluorescence protection assay. This strategy is based on our reasoning that interaction of aptamer with its protein target may dramatically increase steric hindrance, which protects the fluorophore, fluorescein isothiocyannate (FITC), labeled at the binding pocket from accessing and quenching by the FITC antibody. The aptamer sensor strategy is demonstrated using a model protein target of immunoglobulin E (IgE), a known biomarker associated with atopic allergic diseases. The results reveal that the aptamer sensor shows substantial (>6-fold) fluorescence enhancement in response to the protein target, thereby verifying the mechanism of fluorescence protection. Moreover, the aptamer sensor displays improved specificity to other co-existing proteins and a desirable dynamic range within the IgE concentration from 0.1 to 50 nM with a readily achieved detection limit of 0.1 nM. Because of great robustness, easy operation and scalability for parallel assays, the developed homogeneous fluorescence protection assay strategy might create a new methodology for developing aptamer sensors in sensitive, selective detection of proteins.
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Affiliation(s)
- Hong-Qi Wang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P R China
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91
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De Marni ML, Monegal A, Venturini S, Vinati S, Carbone R, de Marco A. Antibody purification-independent microarrays (PIM) by direct bacteria spotting on TiO2-treated slides. Methods 2011; 56:317-25. [PMID: 21736943 DOI: 10.1016/j.ymeth.2011.06.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 06/17/2011] [Accepted: 06/20/2011] [Indexed: 11/30/2022] Open
Abstract
The preparation of effective conventional antibody microarrays depends on the availability of high quality material and on the correct accessibility of the antibody active moieties following their immobilization on the support slide. We show that spotting bacteria that expose recombinant antibodies on their external surface directly on nanostructured-TiO(2) or epoxy slides (purification-independent microarray - PIM) is a simple and reliable alternative for preparing sensitive and specific microarrays for antigen detection. Variable domains of single heavy-chain antibodies (VHHs) against fibroblast growth factor receptor 1 (FGFR1) were used to capture the antigen diluted in serum or BSA solution. The FGFR1 detection was performed by either direct antigen labeling or using a sandwich system in which FGFR1 was first bound to its antibody and successively identified using a labeled FGF. In both cases the signal distribution within each spot was uniform and spot morphology regular. The signal-to-noise ratio of the signal was extremely elevated and the specificity of the system was proved statistically. The LOD of the system for the antigen was calculated being 0.4ng/mL and the dynamic range between 0.4ng/mL and 10μg/mL. The microarrays prepared with bacteria exposing antibodies remain fully functional for at least 31 days after spotting. We finally demonstrated that the method is suitable for other antigen-antibody pairs and expect that it could be easily adapted to further applications such as the display of scFv and IgG antibodies or the autoantibody detection using protein PIMs.
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92
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Anderson RR, Hu W, Noh JW, Dahlquist WC, Ness SJ, Gustafson TM, Richards DC, Kim S, Mazzeo BA, Woolley AT, Nordin GP. Transient deflection response in microcantilever array integrated with polydimethylsiloxane (PDMS) microfluidics. LAB ON A CHIP 2011; 11:2088-96. [PMID: 21547316 DOI: 10.1039/c1lc20025a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We report the integration of a nanomechanical sensor consisting of 16 silicon microcantilevers with polydimethylsiloxane (PDMS) microfluidics. For microcantilevers positioned near the bottom of a microfluidic flow channel, a transient differential analyte concentration for the top versus bottom surface of each microcantilever is created when an analyte-bearing fluid is introduced into the flow channel (which is initially filled with a non-analyte containing solution). We use this effect to characterize a bare (nonfunctionalized) microcantilever array in which the microcantilevers are simultaneously read out with our recently developed high sensitivity in-plane photonic transduction method. We first examine the case of non-specific binding of bovine serum albumin (BSA) to silicon. The average maximum transient microcantilever deflection in the array is -1.6 nm, which corresponds to a differential surface stress of only -0.23 mN m(-1). This is in excellent agreement with the maximum differential surface stress calculated based on a modified rate equation in conjunction with finite element simulation. Following BSA adsorption, buffer solutions with different pH are introduced to further study microcantilever array transient response. Deflections of 20-100 nm are observed (2-14 mN m(-1) differential surface stress). At a flow rate of 5 μL min(-1), the average measured temporal width (FWHM) of the transient response is 5.3 s for BSA non-specific binding and 0.74 s for pH changes.
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Affiliation(s)
- Ryan R Anderson
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA
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93
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Pan H, Xu Y, Wu S, Zhang B, Tang J. Molecular interactions in self-assembly monolayers on gold-coated microcantilever electrodes. NANOTECHNOLOGY 2011; 22:225503. [PMID: 21454929 DOI: 10.1088/0957-4484/22/22/225503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An electrochemical microcantilever (EMC) was used to study the intermolecular interaction of self-assembly monolayers (SAMs) with different n-alkanethiols chain lengths (n = 0, 4, 6, 8, 12, 16) on a Au-coated microcantilever surface. Comparing potential cycling and steps in NaClO(4) solution within the same potential range, the deflection rate of bare microcantilevers is much smaller for the former which revealed that potential excitation, i.e. the surface charge, played the dominant role in driving the instant and large deflection of the bare microcantilever, while the smaller deflection amplitude of the former implied that adsorption of ClO(4)( - ) had an adverse effect on the potential-induced stress. Upon adsorption of SAMs, the deflection amplitude of the microcantilever under the potential step was much smaller than that of a bare microcantilever, and linearly decreased with the chain length increasing for n ≤ 8 (the linear correlation coefficient and the slope are 0.98 and about - 10.4 nm per CH(2) unit, respectively), following a transition (8 ≤ n ≤ 12) to a stable state (n ≥ 12). The decrease of deflection amplitude and faster decay of deflection rate of the SAMs modified microcantilever under the potential step implyed increasing compactness of the SAMs with longer chains.
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Affiliation(s)
- Hongqing Pan
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Changchun, People's Republic of China
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94
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Gruber K, Horlacher T, Castelli R, Mader A, Seeberger PH, Hermann BA. Cantilever array sensors detect specific carbohydrate-protein interactions with picomolar sensitivity. ACS NANO 2011; 5:3670-3678. [PMID: 21388220 DOI: 10.1021/nn103626q] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Advances in carbohydrate sequencing technologies have revealed the tremendous complexity of the glycome. This complexity reflects the structural and chemical diversity of carbohydrates and is greater than that of proteins and oligonucleotides. The next step in understanding the biological function of carbohydrates requires the identification and quantification of carbohydrate interactions with other biomolecules, in particular, with proteins. To this end, we have developed a cantilever array biosensor with a self-assembling carbohydrate-based sensing layer that selectively and sensitively detects carbohydrate-protein binding interactions. Specifically, we examined binding of mannosides and the protein cyanovirin-N, which binds and blocks the human immunodeficiency virus (HIV). Cyanovirin-N binding to immobilized oligomannosides on the cantilever resulted in mechanical surface stress that is transduced into a mechanical force and cantilever bending. The degree and duration of cantilever deflection correlates with the interaction's strength, and comparative binding experiments reveal molecular binding preferences. This study establishes that carbohydrate-based cantilever biosensors are a robust, label-free, and scalable means to analyze carbohydrate-protein interactions and to detect picomolar concentrations of carbohydrate-binding proteins.
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Affiliation(s)
- Kathrin Gruber
- Department of Physics, Ludwig-Maximilians-Universität Munich, Walther-Meissner-Strasse 8, 85748 Garching, Germany
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95
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Bellan LM, Wu D, Langer RS. Current trends in nanobiosensor technology. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2011; 3:229-46. [PMID: 21391305 PMCID: PMC4126610 DOI: 10.1002/wnan.136] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The development of tools and processes used to fabricate, measure, and image nanoscale objects has lead to a wide range of work devoted to producing sensors that interact with extremely small numbers (or an extremely small concentration) of analyte molecules. These advances are particularly exciting in the context of biosensing, where the demands for low concentration detection and high specificity are great. Nanoscale biosensors, or nanobiosensors, provide researchers with an unprecedented level of sensitivity, often to the single molecule level. The use of biomolecule-functionalized surfaces can dramatically boost the specificity of the detection system, but can also yield reproducibility problems and increased complexity. Several nanobiosensor architectures based on mechanical devices, optical resonators, functionalized nanoparticles, nanowires, nanotubes, and nanofibers have been demonstrated in the lab. As nanobiosensor technology becomes more refined and reliable, it is likely it will eventually make its way from the lab to the clinic, where future lab-on-a-chip devices incorporating an array of nanobiosensors could be used for rapid screening of a wide variety of analytes at low cost using small samples of patient material.
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Affiliation(s)
- Leon M Bellan
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
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96
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Bellan LM, Wu D, Langer RS. Current trends in nanobiosensor technology. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2011. [PMID: 21391305 DOI: 10.1002/wnan.v3.310.1002/wnan.136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
The development of tools and processes used to fabricate, measure, and image nanoscale objects has lead to a wide range of work devoted to producing sensors that interact with extremely small numbers (or an extremely small concentration) of analyte molecules. These advances are particularly exciting in the context of biosensing, where the demands for low concentration detection and high specificity are great. Nanoscale biosensors, or nanobiosensors, provide researchers with an unprecedented level of sensitivity, often to the single molecule level. The use of biomolecule-functionalized surfaces can dramatically boost the specificity of the detection system, but can also yield reproducibility problems and increased complexity. Several nanobiosensor architectures based on mechanical devices, optical resonators, functionalized nanoparticles, nanowires, nanotubes, and nanofibers have been demonstrated in the lab. As nanobiosensor technology becomes more refined and reliable, it is likely it will eventually make its way from the lab to the clinic, where future lab-on-a-chip devices incorporating an array of nanobiosensors could be used for rapid screening of a wide variety of analytes at low cost using small samples of patient material.
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Affiliation(s)
- Leon M Bellan
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
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97
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Arlett J, Myers E, Roukes M. Comparative advantages of mechanical biosensors. NATURE NANOTECHNOLOGY 2011; 6:203-15. [PMID: 21441911 PMCID: PMC3839312 DOI: 10.1038/nnano.2011.44] [Citation(s) in RCA: 444] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Mechanical interactions are fundamental to biology. Mechanical forces of chemical origin determine motility and adhesion on the cellular scale, and govern transport and affinity on the molecular scale. Biological sensing in the mechanical domain provides unique opportunities to measure forces, displacements and mass changes from cellular and subcellular processes. Nanomechanical systems are particularly well matched in size with molecular interactions, and provide a basis for biological probes with single-molecule sensitivity. Here we review micro- and nanoscale biosensors, with a particular focus on fast mechanical biosensing in fluid by mass- and force-based methods, and the challenges presented by non-specific interactions. We explain the general issues that will be critical to the success of any type of next-generation mechanical biosensor, such as the need to improve intrinsic device performance, fabrication reproducibility and system integration. We also discuss the need for a greater understanding of analyte-sensor interactions on the nanoscale and of stochastic processes in the sensing environment.
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Affiliation(s)
| | | | - M.L. Roukes
- Kavli Nanoscience Institute and Departments of Physics, Applied Physics, and Bioengineering, California Institute of Technology, MC 149-33 Pasadena, California 91125, USA.
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98
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Buchapudi KR, Huang X, Yang X, Ji HF, Thundat T. Microcantilever biosensors for chemicals and bioorganisms. Analyst 2011; 136:1539-56. [PMID: 21394347 DOI: 10.1039/c0an01007c] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In the last fifteen years, microcantilevers (MCLs) have been emerging as a sensitive tool for the detection of chemicals and bioorganisms. Because of their small size, lightweight, and high surface-to-volume ratio, MCL-based sensors improve our capability to detect and identify biological agents by orders of magnitude. A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component. The MCL biosensors have recently been reviewed in several papers. All of these papers were organized based on the sensing biological elements (antibody, enzyme, proteins, etc.) for recognition of analytes. In this review, we intend to summarize the microcantilever biosensors in a format of each specific chemical and bioorganism species to make information on individual biosensors easily accessible. We did this to aid researchers to locate relevant references.
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Affiliation(s)
- Koutilya R Buchapudi
- Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA 71272, USA
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99
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Yoshikawa G, Akiyama T, Gautsch S, Vettiger P, Rohrer H. Nanomechanical membrane-type surface stress sensor. NANO LETTERS 2011; 11:1044-1048. [PMID: 21314159 DOI: 10.1021/nl103901a] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nanomechanical cantilever sensors have been emerging as a key device for real-time and label-free detection of various analytes ranging from gaseous to biological molecules. The major sensing principle is based on the analyte-induced surface stress, which makes a cantilever bend. In this letter, we present a membrane-type surface stress sensor (MSS), which is based on the piezoresistive read-out integrated in the sensor chip. The MSS is not a simple "cantilever," rather it consists of an "adsorbate membrane" suspended by four piezoresistive "sensing beams," composing a full Wheatstone bridge. The whole analyte-induced isotropic surface stress on the membrane is efficiently transduced to the piezoresistive beams as an amplified uniaxial stress. Evaluation of a prototype MSS used in the present experiments demonstrates a high sensitivity which is comparable with that of optical methods and a factor of more than 20 higher than that obtained with a standard piezoresistive cantilever. The finite element analyses indicate that changing dimensions of the membrane and beams can substantially increase the sensitivity further. Given the various conveniences and advantages of the integrated piezoresistive read-out, this platform is expected to open a new era of surface stress-based sensing.
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Affiliation(s)
- Genki Yoshikawa
- World Premier International (WPI) Research Center, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
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100
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Oliviero G, Federici S, Colombi P, Bergese P. On the difference of equilibrium constants of DNA hybridization in bulk solution and at the solid-solution interface. J Mol Recognit 2011; 24:182-7. [DOI: 10.1002/jmr.1019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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