title: Gold nanocatalyst-based immunosensing strategy accompanying catalytic reduction of 4-nitrophenol for sensitive monitoring of chloramphenicol residue.
abstract: A new competitive-type immunosensing system based on gold nanoparticles toward catalytic reduction of 4-nitrophenol (4-NP) was developed for sensitive monitoring of antibiotic residue (chloramphenicol, CAP, used in this case) by using ultraviolet-visible (UV-vis) spectrometry. Gold nanoparticle (AuNP) with 16 nm in diameter was initially synthesized and functionalized with CAP-bovine serum albumin (CAP-BSA) conjugate, which were used as the competitor on monoclonal anti-CAP antibody-coated polystyrene microtiter plate (MTP). In the presence of target CAP, the labeled CAP-BSA on the AuNP competed with target CAP for the immobilized antibody on the MTP. The conjugated amount of CAP-BSA-AuNP on the MTP decreased with the increase of target CAP in the sample. Upon addition of 4-NP and NaBH4 into the MTP, the carried AuNP could catalytically reduce 4-NP to 4-aminophenol (4-AP), and the as-produced 4-AP could be monitored by using UV-vis absorption spectroscopy. Experimental results indicated that the absorbance at 403 nm increased with the increment of target CAP concentration in the sample, and exhibited a dynamic range from 0.1 to 100 ng mL(-1) with a detection limit (LOD) of 0.03 ng mL(-1) at the 3s(blank) level. Intra- and inter-assay coefficients of variation were lower than 5.5% and 8.0%, respectively. In addition, the methodology was evaluated for CAP spiked honey and milk samples, respectively. The recovery was 92-112%.
authors.affiliation: Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, College of Materials and Chemical Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, PR China; Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), Department of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, PR China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Que
authors.affiliation: Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, College of Materials and Chemical Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, PR China.
authors.forename: Dianyong
authors.initials: D
authors.lastname: Tang
authors.affiliation: Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, College of Materials and Chemical Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, PR China.
authors.forename: Biyun
authors.initials: B
authors.lastname: Xia
authors.affiliation: Institute of Environmental and Analytical Science, School of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, PR China. Electronic address: minghua.lu2009@hotmail.com.
authors.forename: Minghua
authors.initials: M
authors.lastname: Lu
authors.affiliation: Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, College of Materials and Chemical Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, PR China; Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), Department of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, PR China. Electronic address: dianping.tang@fzu.edu.cn.
authors.forename: Dianping
authors.initials: D
authors.lastname: Tang
mesh_terms: D000818:Animals; D002384:Catalysis; D002701:Chloramphenicol / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D006722:Honey / Q000032:analysis; D007118:Immunoassay; D053768:Metal Nanoparticles / Q000737:chemistry*; D008892:Milk / Q000737:chemistry; D009596:Nitrophenols / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D009596:Nitrophenols; D002701:Chloramphenicol; D006046:Gold; C024836:4-nitrophenol
keywords: Chloramphenicol; Foodstuff; Gold nanocatalyst; Immunoassay; Ultraviolet–visible spectroscopy