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de Sousa DVM, Orlando RM, Pereira FV. Layer-by-layer assembly of PDDA/MWCNTs thin films as an efficient strategy for extraction of organic compounds from complex samples. J Chromatogr A 2024; 1717:464705. [PMID: 38310702 DOI: 10.1016/j.chroma.2024.464705] [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] [Received: 11/08/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/06/2024]
Abstract
This article presents the assembly and characterization of poly(diallyldimethylammonium chloride)/multi-walled carbon nanotubes (PDDA/MWCNTs) thin films on borosilicate bottles using a layer-by-layer (LBL) approach. The thin films, consisting of 10 bilayers of coating materials, were thoroughly characterized using UV-VIS spectroscopy, scanning electron microscopy (SEM), and zeta potential measurements. The modified bottles were then utilized for the extraction of analytes with diverse acid-base characteristics, including drugs, illicit drugs, and pesticides, from saliva, urine, and surface water samples. The studied analytes can be adsorbed on the surface of the LBL film mainly through hydrogen bonding and/or hydrophobic interactions. Remarkably high extraction percentages of up to 92 % were achieved, accompanied by an impressive enhancement in the analytical signal of up to 12 times when the sample volume was increased from 0.7 to 10 mL. These results highlight the outstanding extraction and sorption capabilities of the developed material. Additionally, the (PDDA/MWCNTs)10 films exhibited notable resistance to extraction and desorption processes, enabling their reuse for at least 5 cycles. The straightforward and cost-effective fabrication of these sorbent materials using the LBL technique, combined with the ability to extract target compounds during sample transportation and/or storage, renders this sample preparation method a promising alternative.
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Affiliation(s)
- Denise V Monteiro de Sousa
- Department of Chemistry, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG CEP 31270-901, Brazil
| | - Ricardo Mathias Orlando
- Department of Chemistry, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG CEP 31270-901, Brazil
| | - Fabiano Vargas Pereira
- Department of Chemistry, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG CEP 31270-901, Brazil.
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2
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Yadav M, Osonga FJ, Sadik OA. Unveiling nano-empowered catalytic mechanisms for PFAS sensing, removal and destruction in water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169279. [PMID: 38123092 DOI: 10.1016/j.scitotenv.2023.169279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/14/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are organofluorine compounds used to manufacture various industrial and consumer goods. Due to their excellent physical and thermal stability ascribed to the strong CF bond, these are ubiquitously present globally and difficult to remediate. Extensive toxicological and epidemiological studies have confirmed these substances to cause adverse health effects. With the increasing literature on the environmental impact of PFAS, the regulations and research have also expanded. Researchers worldwide are working on the detection and remediation of PFAS. Many methods have been developed for their sensing, removal, and destruction. Amongst these methods, nanotechnology has emerged as a sustainable and affordable solution due to its tunable surface properties, high sorption capacities, and excellent reactivities. This review comprehensively discusses the recently developed nanoengineered materials used for detecting, sequestering, and destroying PFAS from aqueous matrices. Innovative designs of nanocomposites and their efficiency for the sensing, removal, and degradation of these persistent pollutants are reviewed, and key insights are analyzed. The mechanistic details and evidence available to support the cleavage of the CF bond during the treatment of PFAS in water are critically examined. Moreover, it highlights the challenges during PFAS quantification and analysis, including the analysis of intermediates in transitioning nanotechnologies from the laboratory to the field.
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Affiliation(s)
- Manavi Yadav
- Department of Chemistry and Environmental Sciences, New Jersey Institutes of Technology (NJIT), United States of America
| | - Francis J Osonga
- Department of Chemistry and Environmental Sciences, New Jersey Institutes of Technology (NJIT), United States of America
| | - Omowunmi A Sadik
- Department of Chemistry and Environmental Sciences, New Jersey Institutes of Technology (NJIT), United States of America.
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3
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Garg S, Kumar P, Greene GW, Mishra V, Avisar D, Sharma RS, Dumée LF. Nano-enabled sensing of per-/poly-fluoroalkyl substances (PFAS) from aqueous systems - A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 308:114655. [PMID: 35131704 DOI: 10.1016/j.jenvman.2022.114655] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/01/2022] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Per-/poly-fluoroalkyl substances (PFAS) are an emerging class of environmental contaminants used as an additive across various commodity and fire-retardant products, for their unique thermo-chemical stability, and to alter their surface properties towards selective liquid repellence. These properties also make PFAS highly persistent and mobile across various environmental compartments, leading to bioaccumulation, and causing acute ecotoxicity at all trophic levels particularly to human populations, thus increasing the need for monitoring at their repositories or usage sites. In this review, current nano-enabled methods towards PFAS sensing and its monitoring in wastewater are critically discussed and benchmarked against conventional detection methods. The discussion correlates the materials' properties to the sensitivity, responsiveness, and reproducibility of the sensing performance for nano-enabled sensors in currently explored electrochemical, spectrophotometric, colorimetric, optical, fluorometric, and biochemical with limits of detection of 1.02 × 10-6 μg/L, 2.8 μg/L, 1 μg/L, 0.13 μg/L, 6.0 × 10-5 μg/L, and 4.141 × 10-7 μg/L respectively. The cost-effectiveness of sensing platforms plays an important role in the on-site analysis success and upscalability of nano-enabled sensors. Environmental monitoring of PFAS is a step closer to PFAS remediation. Electrochemical and biosensing methods have proven to be the most reliable tools for future PFAS sensing endeavors with very promising detection limits in an aqueous matrix, short detection times, and ease of fabrication.
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Affiliation(s)
- Shafali Garg
- University of Delhi, Bioresources and Environmental Biotechnology Laboratory, Department of Environmental Studies, India
| | - Pankaj Kumar
- University of Delhi, Bioresources and Environmental Biotechnology Laboratory, Department of Environmental Studies, India
| | - George W Greene
- Deakin University, Institute for Frontier Materials, Burwood, Melbourne, Victoria, Australia
| | - Vandana Mishra
- University of Delhi, Bioresources and Environmental Biotechnology Laboratory, Department of Environmental Studies, India; University of Delhi, Delhi School of Climate Change and Sustainability, Institute of Eminence, Delhi, 110007, India
| | - Dror Avisar
- Tel Aviv University, School for Environmental and Earth Sciences, Water Research Center, Tel Aviv, Israel
| | - Radhey Shyam Sharma
- University of Delhi, Bioresources and Environmental Biotechnology Laboratory, Department of Environmental Studies, India; University of Delhi, Delhi School of Climate Change and Sustainability, Institute of Eminence, Delhi, 110007, India.
| | - Ludovic F Dumée
- Khalifa University, Department of Chemical Engineering, Abu Dhabi, United Arab Emirates; Khalifa University, Center for Membrane and Advanced Water Technology, Abu Dhabi, United Arab Emirates; Khalifa University, Research and Innovation Center on CO(2) and Hydrogen, Abu Dhabi, United Arab Emirates.
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4
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Li J, Su Z, Huang J, Feng W, Wei T, Meng K, Muhammad Y. Performance of biomimetic coating modified fiber incorporated styrene butadiene styrene modified asphalt. J Appl Polym Sci 2021. [DOI: 10.1002/app.49967] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jing Li
- School of Chemistry and Chemical Engineering Guangxi University Nanning China
| | - Zhibin Su
- School of Chemistry and Chemical Engineering Guangxi University Nanning China
| | - Junxian Huang
- School of Chemistry and Chemical Engineering Guangxi University Nanning China
| | - Weijie Feng
- School of Chemistry and Chemical Engineering Guangxi University Nanning China
| | - Tingyang Wei
- School of Chemistry and Chemical Engineering Guangxi University Nanning China
| | - Kun Meng
- School of Chemistry and Chemical Engineering Guangxi University Nanning China
| | - Yaseen Muhammad
- School of Chemistry and Chemical Engineering Guangxi University Nanning China
- Institute of Chemical Sciences University of Peshawar Khyber Pakhtunkhwa Pakistan
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5
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Zhu YL, Lian YM, Wang JK, Chen ZP, Yu RQ. Ultrasensitive detection of protein biomarkers by MALDI-TOF mass spectrometry based on ZnFe 2O 4 nanoparticles and mass tagging signal amplification. Talanta 2021; 224:121848. [PMID: 33379064 DOI: 10.1016/j.talanta.2020.121848] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/24/2020] [Accepted: 10/30/2020] [Indexed: 11/30/2022]
Abstract
A facile MALDI-TOF mass spectrometric platform for quantitative analysis of protein biomarkers was developed based on magnetic ZnFe2O4 nanoparticles and mass tagging signal amplification. In this platform, magnetic ZnFe2O4 nanoparticles functionalized with an aptamer of the biomarker of interest was used to magnetically separate silica nanoparticles modified with another aptamer of the target biomarker and a barcoding peptide from solution phase in the presence of the biomarker of interest. After the silica nanoparticles were dissolved by KHF2, the released barcoding peptide was detected by MALDI-TOF mass spectrometry with magnetic ZnFe2O4 nanoparticles used as assisting matrix of laser desorption ionization. Since the mass spectral intensity of the barcoding peptide is directly related to the concentration of the target biomarker, the proposed platform can be applied to the quantification of the target biomarker in complex biological samples. The effectiveness of the proposed platform was tested on the detection of carcinoembryonic antigen (CEA) in serum. Experimental results revealed that the proposed platform could achieve quite reliable quantitative results for CEA in human serum samples with accuracy comparable to a commercial CEA ELISA Kit. Its limit of detection and limit of quantification for CEA were estimated to be 0.6 × 10-3 and 1.8 × 10-3 ng/mL, respectively, considerably lower than the corresponding values reported in literature. Due to its features of simplicity in design, extremely low background signal, high sensitivity and selectivity, the proposed method can be further developed to be a competitive alternative for the quantification of CEA and other protein biomarkers as well.
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Affiliation(s)
- Yan-Li Zhu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China
| | - Yan-Mei Lian
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China
| | - Ji-Kai Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China
| | - Zeng-Ping Chen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China.
| | - Ru-Qin Yu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China
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6
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Zeng L, Zhang X, Wang X, Cheng D, Li R, Han B, Wu M, Zhuang Z, Ren A, Zhou Y, Jing T. Simultaneous fluorescence determination of bisphenol A and its halogenated analogs based on a molecularly imprinted paper-based analytical device and a segment detection strategy. Biosens Bioelectron 2021; 180:113106. [PMID: 33647791 DOI: 10.1016/j.bios.2021.113106] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/25/2021] [Accepted: 02/16/2021] [Indexed: 11/25/2022]
Abstract
Bisphenol A (BPA) and its halogenated analogs tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) are common environmental contaminants and a method for their simultaneous determination is urgently needed. A paper-based analytical device (PAD) was prepared using a metal-organic framework of UiO-66-NH2 coated with molecularly imprinted polymers (MIPs) using TBBPA as a template. The maximum adsorption capacity was 120.94 mg g-1 and the imprinting factor was 4.07. The selective recognition ability of this PAD enabled the effective separation of TBBPA, TCBPA and BPA based on paper chromatography. Subsequently, the PAD cut into segments were used individually to determine the presence of target chemicals using a highly sensitive fluorescent method. Under ultraviolet light irradiation, UiO-66-NH2 acts as a photocatalyst to produce reactive oxygen species (ROS) that degrade TBBPA, TCBPA or BPA in the imprinted cavities and the fluorescent signal of 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) added as a ROS probe enabled the indirect determination of target chemicals. This method could determine BPA and its halogenated analogs in dust samples simultaneously with detection limits ranging from 0.14 to 0.30 ng g-1. The intraday relative standard deviation (RSD) was ≤6.8% and interday RSD was ≤8.1%. The recoveries ranged from 91.0 to 105.6% with RSD values that were ≤7.5%. The results stemmed from this method were consistent with those obtained from LC-MS/MS. It is an environmentally-friendly approach due to the degradation of target pollutants and possesses many advantages such as high selectivity, low cost and easy-to-fabrication.
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Affiliation(s)
- Lingshuai Zeng
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Xiu Zhang
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Xiu Wang
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Danqi Cheng
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Ruifang Li
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Bin Han
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Minmin Wu
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Zhijia Zhuang
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Annan Ren
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Yikai Zhou
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China
| | - Tao Jing
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China.
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Yu J, Di S, Yu H, Ning T, Yang H, Zhu S. Insights into the structure-performance relationships of extraction materials in sample preparation for chromatography. J Chromatogr A 2020; 1637:461822. [PMID: 33360779 DOI: 10.1016/j.chroma.2020.461822] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/13/2020] [Accepted: 12/14/2020] [Indexed: 01/23/2023]
Abstract
Sample preparation is one of the most crucial steps in analytical processes. Commonly used methods, including solid-phase extraction, dispersive solid-phase extraction, dispersive magnetic solid-phase extraction, and solid-phase microextraction, greatly depend on the extraction materials. In recent decades, a vast number of materials have been studied and used in sample preparation for chromatography. Due to the unique structural properties, extraction materials significantly improve the performance of extraction devices. Endowing extraction materials with suitable structural properties can shorten the pretreatment process and improve the extraction efficiency and selectivity. To understand the structure-performance relationships of extraction materials, this review systematically summarizes the structural properties, including the pore size, pore shape, pore volume, accessibility of active sites, specific surface area, functional groups and physicochemical properties. The mechanisms by which the structural properties influence the extraction performance are also elucidated in detail. Finally, three principles for the design and synthesis of extraction materials are summarized. This review can provide systematic guidelines for synthesizing extraction materials and preparing extraction devices.
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Affiliation(s)
- Jing Yu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, P. R. China
| | - Siyuan Di
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, P. R. China
| | - Hao Yu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, P. R. China
| | - Tao Ning
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, P. R. China
| | - Hucheng Yang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, P. R. China
| | - Shukui Zhu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, P. R. China.
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Luo K, Yang B, Guo W, Sun Q, Dan O, Lin Z, Cai Z. Surface-enhanced laser desorption/ionization mass spectrometry for rapid analysis of organic environmental pollutants by using polydopamine nanospheres as a substrate. Analyst 2020; 145:5664-5669. [PMID: 32643716 DOI: 10.1039/d0an00895h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Polydopamine nanospheres (PDA) were designed to serve as a new substrate for surface-enhanced desorption/ionization mass spectrometry (SELDI-MS). Compared with conventional organic matrices, the PDA substrate showed superior LDI performance for analyzing a wide variety of environmental pollutants, including polycyclic aromatic hydrocarbons, bisphenols, benzophenones, sulfonamides, perfluorinated compounds and estrogens. Benzoapyrene was used to evaluate the ability of quantitative analysis and its corresponding limit of detection (LOD) of as low as 0.1 ng was achieved. High sensitivity and good reproducibility of PDA-based SELDI-MS allowed us to determine ultratrace PAHs in airborne particulate matters (PM2.5), and the corresponding concentration of BaP in different PM2.5 were 5.32, 8.97 and 9.79 ng m-3. Significantly, PDA exhibits the characteristics of simple synthesis, low cost, non-toxicity and less matrix interference, which provides the possibility for the sensitive analysis of organic small molecule pollutants at low concentrations in complex environmental samples.
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Affiliation(s)
- Kailong Luo
- Ministry of Education Key Laboratory of Analytical Science for Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
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Covalent-organic frameworks as adsorbent and matrix of SALDI-TOF MS for the enrichment and rapid determination of fluorochemicals. Talanta 2019; 194:522-527. [DOI: 10.1016/j.talanta.2018.10.071] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 10/02/2018] [Accepted: 10/21/2018] [Indexed: 11/19/2022]
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10
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Manjubaashini N, Kesavan MP, Rajesh J, Daniel Thangadurai T. Multispectroscopic and bioimaging approach for the interaction of rhodamine 6G capped gold nanoparticles with bovine serum albumin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 183:374-384. [PMID: 29763760 DOI: 10.1016/j.jphotobiol.2018.05.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/30/2018] [Accepted: 05/04/2018] [Indexed: 02/06/2023]
Abstract
Binding interaction of Bovine Serum Albumin (BSA) with newly prepared rhodamine 6G-capped gold nanoparticles (Rh6G-Au NPs) under physiological conditions (pH 7.2) was investigated by a wide range of photophysical techniques. Rh6G-Au NPs caused the static quenching of the intrinsic fluorescence of BSA that resulted from the formation of ground-state complex between BSA and Rh6G-Au NPs. The binding constant from fluorescence quenching method (Ka = 1.04 × 104 L mol-1; LoD = 14.0 μM) is in accordance with apparent association constant (Kapp = 1.14 × 101 M-1), which is obtained from absorption spectral studies. Förster resonance energy transfer (FRET) efficiency between the tryptophan (Trp) residue of BSA and fluorophore of Rh6G-Au NPs during the interaction was calculated to be 90%. The free energy change (ΔG = -23.07 kJ/mol) of BSA-Rh6G-Au NPs complex was calculated based on modified Stern-Volmer Plot. The time-resolved fluorescence analysis confirmed that quenching of BSA follows static mechanism through the formation of ground state complex. Furthermore, synchronous and three-dimensional fluorescence measurement, Raman spectral analysis and Circular Dichroism spectrum results corroborate the strong binding between Rh6G-Au NPs and BSA, which causes the conformational changes on BSA molecule. In addition, fluorescence imaging experiments of BSA in living human breast cancer (HeLa) cells was successfully demonstrated, which articulated the value of Rh6G-Au NPs practical applications in biological systems.
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Affiliation(s)
- N Manjubaashini
- Department of Nanoscience and Technology, Sri Ramakrishana Engineering College, Coimbatore, Tamilnadu 641 022, India
| | | | | | - T Daniel Thangadurai
- Department of Nanoscience and Technology, Sri Ramakrishana Engineering College, Coimbatore, Tamilnadu 641 022, India.
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