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Li G, Fan J, Zhang T, Gao T, Chong Y, Liang M, Liang S, Hu B, Yi L, Zhao L, Castel H. Honeycomb-Inspired Surface-Enhanced Raman Scattering Microarray for Large-Area Automated Testing of Urease in Saliva Samples. ACS Sens 2024; 9:2031-2042. [PMID: 38593209 DOI: 10.1021/acssensors.4c00006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Surface-enhanced Raman scattering (SERS) technology, as an important analytical tool, has been widely applied in the field of chemical and biomedical sensing. Automated testing is often combined with biochemical analysis technologies to shorten the detection time and minimize human error. The present SERS substrates for sample detection are time-consuming and subject to high human error, which are not conducive to the combination of SERS and automated testing. Here, a novel honeycomb-inspired SERS microarray is designed for large-area automated testing of urease in saliva samples to shorten the detection time and minimize human error. The honeycomb-inspired SERS microarray is decorated with hexagonal microwells and a homogeneous distribution of silver nanostars. Compared with the other four common SERS substrates, the optimal honeycomb-inspired SERS microarray exhibits the best SERS performance. The RSD of 100 SERS spectra continuously collected from saliva samples is 6.56%, and the time of one detection is reduced from 5 min to 10 s. There is a noteworthy linear relationship with a R2 of 0.982 between SERS intensity and urease concentration, indicating the quantitative detection capability of the urease activity in saliva samples. The honeycomb-inspired SERS microarray, combined with automated testing, provides a new way in which SERS technology can be widely used in biomedical applications.
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Affiliation(s)
- Guoqian Li
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Jinkun Fan
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Ting Zhang
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Ting Gao
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Yuying Chong
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Minghui Liang
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Shijian Liang
- Guangzhou Betop Scientific Ltd., Guangzhou 510308, Guandong, China
| | - Bo Hu
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Langlang Yi
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Lei Zhao
- School of Life Science and Technology, Xidian University, Xi'an 710126, Shaanxi, China
| | - Helene Castel
- Institute of Research and Biomedical Innovation, University of Rouen Normandy, Mont-Saint, Aignan, 76821, France
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Silva-Holguín PN, Garibay-Alvarado JA, Reyes-López SY. Silver Nanoparticles: Multifunctional Tool in Environmental Water Remediation. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1939. [PMID: 38730746 PMCID: PMC11084846 DOI: 10.3390/ma17091939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 04/09/2024] [Accepted: 04/15/2024] [Indexed: 05/13/2024]
Abstract
Water pollution is a worldwide environmental and health problem that requires the development of sustainable, efficient, and accessible technologies. Nanotechnology is a very attractive alternative in environmental remediation processes due to the multiple properties that are conferred on a material when it is at the nanometric scale. This present review focuses on the understanding of the structure-physicochemical properties-performance relationships of silver nanoparticles, with the objective of guiding the selection of physicochemical properties that promote greater performance and are key factors in their use as antibacterial agents, surface modifiers, colorimetric sensors, signal amplifiers, and plasmonic photocatalysts. Silver nanoparticles with a size of less than 10 nm, morphology with a high percentage of reactive facets {111}, and positive surface charge improve the interaction of the nanoparticles with bacterial cells and induce a greater antibacterial effect. Adsorbent materials functionalized with an optimal concentration of silver nanoparticles increase their contact area and enhance adsorbent capacity. The use of stabilizing agents in silver nanoparticles promotes selective adsorption of contaminants by modifying the surface charge and type of active sites in an adsorbent material, in addition to inducing selective complexation and providing stability in their use as colorimetric sensors. Silver nanoparticles with complex morphologies allow the formation of hot spots or chemical or electromagnetic bonds between substrate and analyte, promoting a greater amplification factor. Controlled doping with nanoparticles in photocatalytic materials produces improvements in their electronic structural properties, promotes changes in charge transfer and bandgap, and improves and expands their photocatalytic properties. Silver nanoparticles have potential use as a tool in water remediation, where by selecting appropriate physicochemical properties for each application, their performance and efficiency are improved.
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Affiliation(s)
| | | | - Simón Yobanny Reyes-López
- Laboratorio de Materiales Híbridos Nanoestructurados, Departamento de Ciencias Químico-Biológicas, Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Envolvente del PRONAF y Estocolmo s/n, Ciudad Juárez 32300, Mexico; (P.N.S.-H.)
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Taheri-Ledari R, Ganjali F, Zarei-Shokat S, Dinmohammadi R, Asl FR, Emami A, Mojtabapour ZS, Rashvandi Z, Kashtiaray A, Jalali F, Maleki A. Plasmonic porous micro- and nano-materials based on Au/Ag nanostructures developed for photothermal cancer therapy: challenges in clinicalization. NANOSCALE ADVANCES 2023; 5:6768-6786. [PMID: 38059020 PMCID: PMC10696950 DOI: 10.1039/d3na00763d] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/13/2023] [Indexed: 12/08/2023]
Abstract
Photothermal therapy (PTT) has developed in recent decades as a relatively safe method for the treatment of cancers. Recently, various species of gold and silver (Au and Ag) nanostructures have been developed and investigated to achieve PTT due to their highly localized surface plasmon resonance (LSPR) effect. Concisely, the collective oscillation of electrons on the surface of Au and Ag nanostructures upon exposure to a specific wavelength (depending on their size and shape) and further plasmonic resonance leads to the heating of the surface of these particles. Hence, porous species can be equipped with tiny plasmonic ingredients that add plasmonic properties to therapeutic cargoes. In this case, a precise review of the recent achievements is very important to figure out to what extent plasmonic photothermal therapy (PPTT) by Au/Ag-based plasmonic porous nanomedicines successfully treated cancers with satisfactory biosafety. Herein, we classify the various species of LSPR-active micro- and nano-materials. Moreover, the routes for the preparation of Ag/Au-plasmonic porous cargoes and related bench assessments are carefully reviewed. Finally, as the main aim of this study, principal requirements for the clinicalization of Ag/Au-plasmonic porous cargoes and their further challenges are discussed, which are critical for specialists in this field.
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Affiliation(s)
- Reza Taheri-Ledari
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Fatemeh Ganjali
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Simindokht Zarei-Shokat
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Reihane Dinmohammadi
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Fereshteh Rasouli Asl
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Ali Emami
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Zahra Sadat Mojtabapour
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Zahra Rashvandi
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Amir Kashtiaray
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Farinaz Jalali
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
| | - Ali Maleki
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology Tehran 16846-13114 Iran +98 2173021584 +98 21 77240640-50
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Damasceno GHB, Carvalho WOF, Mejía-Salazar JR. Design of Plasmonic Yagi-Uda Nanoantennas for Chip-Scale Optical Wireless Communications. SENSORS (BASEL, SWITZERLAND) 2022; 22:7336. [PMID: 36236435 PMCID: PMC9570515 DOI: 10.3390/s22197336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Optical wireless transmission has recently become a major cutting-edge alternative for on-chip/inter-chip communications with higher transmission speeds and improved power efficiency. Plasmonic nanoantennas, the building blocks of this new nanoscale communication paradigm, require precise design to have directional radiation and improved communication ranges. Particular interest has been paid to plasmonic Yagi-Uda, i.e., the optical analog of the conventional Radio Frequency (RF) Yagi-Uda design, which may allow directional radiation of plasmonic fields. However, in contrast to the RF model, an overall design strategy for the directional and optimized front-to-back ratio of the radiated far-field patterns is lacking. In this work, a guide for the optimized design of Yagi-Uda plasmonic nanoantennas is shown. In particular, five different design conditions are used to study the effects of sizes and spacing between the constituent parts (made of Au). Importantly, it is numerically demonstrated (using the scattered fields) that closely spaced nanoantenna elements are not appropriated for directional light-to-plasmon conversion/radiation. In contrast, if the elements of the nanoantenna are widely spaced, the structure behaves like a one-dimensional array of nanodipoles, producing a funnel-like radiation pattern (not suitable for on-chip wireless optical transmission). Therefore, based on the results here, it can be concluded that the constituent metallic rib lengths must be optimized to exhibit the resonance at the working wavelength, whilst their separations should follow the relation λeff/π, where λeff indicates the effective wavelength scaling for plasmonic nanostructures.
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Völkl A, Klupp Taylor RN. Investigation and mitigation of reagent ageing during the continuous flow synthesis of patchy particles. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.03.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Khabarov K, Nouraldeen M, Tikhonov S, Lizunova A, Seraya O, Filalova E, Ivanov V. Comparison of Aerosol Pt, Au and Ag Nanoparticles Agglomerates Laser Sintering. MATERIALS (BASEL, SWITZERLAND) 2021; 15:227. [PMID: 35009372 PMCID: PMC8745795 DOI: 10.3390/ma15010227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/25/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
In this paper, we investigated the interaction of nanosecond pulsed-periodic infrared (IR) laser radiation at a 50 and 500 Hz repetition rate with aerosol platinum (Pt) and silver (Ag) nanoparticles agglomerates obtained in a spark discharge. Results showed the complete transformation of Pt dendrite-like agglomerates with sizes of 300 nm into individual spherical nanoparticles directly in a gas flow under 1053 nm laser pulses with energy density 3.5 mJ/cm2. Notably, the critical energy density required for this process depended on the size distribution and extinction of agglomerates nanoparticles. Based on the extinction cross-section spectra results, Ag nanoparticles exhibit a weaker extinction in the IR region in contrast to Pt, so they were not completely modified even under the pulses with energy density up to 12.7 mJ/cm2. The obtained results for Ag and Pt laser sintering were compared with corresponding modification of gold (Au) nanoparticles studied in our previous work. Here we considered the sintering mechanisms for Ag, Pt and Au nanoparticles agglomerates in the aerosol phase and proposed the model of their laser sintering based on one-stage for Pt agglomerates and two-stage shrinkage processes for Au and Ag agglomerates.
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Luo X, Zhu J, Jia W, Fang N, Wu P, Cai C, Zhu JJ. Boosting Long-Range Surface-Enhanced Raman Scattering on Plasmonic Nanohole Arrays for Ultrasensitive Detection of MiRNA. ACS APPLIED MATERIALS & INTERFACES 2021; 13:18301-18313. [PMID: 33821612 DOI: 10.1021/acsami.1c01834] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A fundamental challenge, particularly, in surface-enhanced Raman scattering (SERS) analysis is the detection of analytes that are distant from the sensing surface. To tackle this challenge, we herein report a long-range SERS (LR-SERS) substrate supporting an extension of electric field afforded by long-range surface plasmon resonance (LRSPR) excited in symmetrical dielectric environments. The LR-SERS substrate has a sandwich configuration with a triangle-shaped gold nanohole array embedded between two dielectrics with similar refractive indices (i.e., MgF2 and water). The finite-difference time-domain simulation was applied to guide the design of the LR-SERS substrate, which was engineered to have a wavelength-matched LRSPR with 785 nm excitation. The simulations predict that the LR-SERS substrate exhibits great SERS enhancement at distances of more than 10 nm beyond its top surface, and the enhancement factor (EF) has been improved by three orders of magnitude on LR-SERS substrates compared to that on conventional substrates. The experimental results show good agreement with the simulations, an EF of 4.1 × 105 remains available at 22 nm above the LR-SERS substrate surface. The LR-SERS substrate was further applied as a sensing platform to detect microRNA (miRNA) let-7a coupled with a hybridization chain reaction (HCR) strategy. The developed sensor displays a wide linear range from 10 aM to 1 nM and an ultralow detection limit of 8.5 aM, making it the most sensitive among the current detection strategies for miRNAs based on the SERS-HCR combination to the best of our knowledge.
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Affiliation(s)
- Xiaojun Luo
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Jingtian Zhu
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Wenyu Jia
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Ningning Fang
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Ping Wu
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Chenxin Cai
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Jun-Jie Zhu
- State Key Laboratory of Analytical for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China
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Fiorati A, Bellingeri A, Punta C, Corsi I, Venditti I. Silver Nanoparticles for Water Pollution Monitoring and Treatments: Ecosafety Challenge and Cellulose-Based Hybrids Solution. Polymers (Basel) 2020; 12:E1635. [PMID: 32717864 PMCID: PMC7465245 DOI: 10.3390/polym12081635] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/16/2020] [Accepted: 07/20/2020] [Indexed: 12/26/2022] Open
Abstract
Silver nanoparticles (AgNPs) are widely used as engineered nanomaterials (ENMs) in many advanced nanotechnologies, due to their versatile, easy and cheap preparations combined with peculiar chemical-physical properties. Their increased production and integration in environmental applications including water treatment raise concerns for their impact on humans and the environment. An eco-design strategy that makes it possible to combine the best material performances with no risk for the natural ecosystems and living beings has been recently proposed. This review envisages potential hybrid solutions of AgNPs for water pollution monitoring and remediation to satisfy their successful, environmentally safe (ecosafe) application. Being extremely efficient in pollutants sensing and degradation, their ecosafe application can be achieved in combination with polymeric-based materials, especially with cellulose, by following an eco-design approach. In fact, (AgNPs)-cellulose hybrids have the double advantage of being easily produced using recycled material, with low costs and possible reuse, and of being ecosafe, if properly designed. An updated view of the use and prospects of these advanced hybrids AgNP-based materials is provided, which will surely speed their environmental application with consequent significant economic and environmental impact.
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Affiliation(s)
- Andrea Fiorati
- Department of Chemistry, Materials, and Chemical Engineering “G. Natta” and INSTM Local Unit, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy; (A.F.); (C.P.)
| | - Arianna Bellingeri
- Department of Physical, Earth and Environmental Sciences and INSTM Local Unit, University of Siena, 53100 Siena, Italy; (A.B.); (I.C.)
| | - Carlo Punta
- Department of Chemistry, Materials, and Chemical Engineering “G. Natta” and INSTM Local Unit, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy; (A.F.); (C.P.)
| | - Ilaria Corsi
- Department of Physical, Earth and Environmental Sciences and INSTM Local Unit, University of Siena, 53100 Siena, Italy; (A.B.); (I.C.)
| | - Iole Venditti
- Department of Sciences, Roma Tre University of Rome, via della Vasca Navale 79, 00146 Rome, Italy
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Courrol LC, Espinoza-Culupú A, da Silva PI, de Oliveira Gonçalves K, de Oliveira Silva FR, Borges MM. Antibacterial and Antitumoral Activities of the Spider Acylpolyamine Mygalin Silver Nanoparticles. BIONANOSCIENCE 2020. [DOI: 10.1007/s12668-020-00738-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Rubira RJG, Camacho SA, Martin CS, Mejía-Salazar JR, Reyes Gómez F, da Silva RR, de Oliveira Junior ON, Alessio P, Constantino CJL. Designing Silver Nanoparticles for Detecting Levodopa (3,4-Dihydroxyphenylalanine, L-Dopa) Using Surface-Enhanced Raman Scattering (SERS). SENSORS (BASEL, SWITZERLAND) 2019; 20:E15. [PMID: 31861443 PMCID: PMC6982777 DOI: 10.3390/s20010015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/06/2019] [Accepted: 12/10/2019] [Indexed: 01/05/2023]
Abstract
Detection of the drug Levodopa (3,4-dihydroxyphenylalanine, L-Dopa) is essential for the medical treatment of several neural disorders, including Parkinson's disease. In this paper, we employed surface-enhanced Raman scattering (SERS) with three shapes of silver nanoparticles (nanostars, AgNS; nanospheres, AgNP; and nanoplates, AgNPL) to detect L-Dopa in the nanoparticle dispersions. The sensitivity of the L-Dopa SERS signal depended on both nanoparticle shape and L-Dopa concentration. The adsorption mechanisms of L-Dopa on the nanoparticles inferred from a detailed analysis of the Raman spectra allowed us to determine the chemical groups involved. For instance, at concentrations below/equivalent to the limit found in human plasma (between 10-7-10-8 mol/L), L-Dopa adsorbs on AgNP through its ring, while at 10-5-10-6 mol/L adsorption is driven by the amino group. At even higher concentrations, above 10-4 mol/L, L-Dopa polymerization predominates. Therefore, our results show that adsorption depends on both the type of Ag nanoparticles (shape and chemical groups surrounding the Ag surface) and the L-Dopa concentration. The overall strategy based on SERS is a step forward to the design of nanostructures to detect analytes of clinical interest with high specificity and at varied concentration ranges.
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Affiliation(s)
- Rafael Jesus Gonçalves Rubira
- School of Technology and Applied Sciences, São Paulo State University (UNESP), Presidente Prudente 19060-900 SP, Brazil; (C.S.M.); (P.A.); (C.J.L.C.)
| | - Sabrina Alessio Camacho
- School of Sciences, Humanities and Languages, São Paulo State University (UNESP), Assis 19806-900 SP, Brazil;
| | - Cibely Silva Martin
- School of Technology and Applied Sciences, São Paulo State University (UNESP), Presidente Prudente 19060-900 SP, Brazil; (C.S.M.); (P.A.); (C.J.L.C.)
| | | | - Faustino Reyes Gómez
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, São Carlos 13560-970 SP, Brazil; (F.R.G.); (R.R.d.S.)
| | - Robson Rosa da Silva
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, São Carlos 13560-970 SP, Brazil; (F.R.G.); (R.R.d.S.)
| | | | - Priscila Alessio
- School of Technology and Applied Sciences, São Paulo State University (UNESP), Presidente Prudente 19060-900 SP, Brazil; (C.S.M.); (P.A.); (C.J.L.C.)
| | - Carlos José Leopoldo Constantino
- School of Technology and Applied Sciences, São Paulo State University (UNESP), Presidente Prudente 19060-900 SP, Brazil; (C.S.M.); (P.A.); (C.J.L.C.)
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Ag Nanostructures with Spikes on Adhesive Tape as a Flexible Sers-Active Substrate for In Situ Trace Detection of Pesticides on Fruit Skin. NANOMATERIALS 2019; 9:nano9121750. [PMID: 31835301 PMCID: PMC6956212 DOI: 10.3390/nano9121750] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/04/2019] [Accepted: 12/06/2019] [Indexed: 11/17/2022]
Abstract
Nanostructures with spikes (NSPs) have been a subject of several surface-enhanced Raman scattering (SERS) applications owing to their significant Raman signal enhancement brought about by the combined effects of interspike coupling and the accumulated induction on the tips of spikes. Thus, NSPs offer great potential as a SERS-active substrate for relevant applications that require a high density of enhanced “hot spots”. In this study, Ag NSPs were synthesized in varying degrees of agglomeration and were thereafter deposited onto a transparent adhesive tape as a flexible substrate for SERS applications, specifically, in the detection of trace amounts of pesticides. These flexible substrates were referred to as Ag NSPs/tape and optimized with an enhancement factor (EF) of ca. 1.7 × 107. A strong resulting signal enhancement could be attributed to an optimal degree of agglomeration and, consequently, the distances among/between spikes. Long spikes on the synthesized core of Ag NSPs tend to be loosely spaced, which are suitable in detecting relatively large molecules that could access the spaces among the spikes where “hot spots” are generally formed. Since one side of the transparent tape is adhesive, the paste-and-peel off method was successful in obtaining phosmet and carbaryl residues from apple peels as reflected in the acquired SERS spectra. In situ trace detection of the pesticides at low concentrations down to 10−7 M could be demonstrated. In situ trace detection of mixed pesticides was possible as the characteristic peaks of both pesticides were observed in equimolar mixtures of the analytes at 10−2 to 10−4 M. This study is, thus, premised upon applying for in situ trace detection on e.g., fruit skin.
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Chaotic Signatures Exhibited by Plasmonic Effects in Au Nanoparticles with Cells. SENSORS 2019; 19:s19214728. [PMID: 31683534 PMCID: PMC6864870 DOI: 10.3390/s19214728] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/21/2019] [Accepted: 10/21/2019] [Indexed: 12/21/2022]
Abstract
The evolution of the optical absorptive effects exhibited by plasmonic nanoparticles was systematically analyzed by electronic signals modulated by a Rössler attractor system. A sol-gel approach was employed for the preparation of the studied Au nanoparticles embedded in a TiO2 thin solid film. The inclusion of the nanoparticles in an inhomogeneous biological sample integrated by human cells deposited in an ITO glass substrate was evaluated with a high level of sensitivity using an opto-electronic chaotic circuit. The optical response of the nanoparticles was determined using nanosecond laser pulses in order to guarantee the sensing performance of the system. It was shown that high-intensity irradiances at a wavelength of 532 nm could promote a change in the absorption band of the localized surface plasmon resonance associated with an increase in the nanoparticle density of the film. Moreover, it was revealed that interferometrically-controlled energy transfer mechanisms can be useful for thermo-plasmonic functions and sharp selective optical damage induced by the vectorial nature of light. Immediate applications of two-wave mixing techniques, together with chaotic effects, can be contemplated in the development of nanostructured sensors and laser-induced controlled explosions, with potential applications for biomedical photo-thermal processes.
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