Premium
Gold Nanoparticles as Dual Functional Sensor to Detect E.coliDH5α as a Model for Gram‐negative Bacteria
Author(s) -
Ma Qun,
Gong Nianchun,
Li Yanle,
Jiang Xi,
Yin Li,
Chen Xueyin,
Huan Shuangyan
Publication year - 2015
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201400536
Subject(s) - chemistry , colloidal gold , bacteria , analytical chemistry (journal) , detection limit , raman scattering , nanoparticle , partial least squares regression , raman spectroscopy , gram negative bacteria , nanotechnology , escherichia coli , chromatography , biochemistry , materials science , optics , genetics , physics , statistics , mathematics , biology , gene
4‐aminothiophenol‐modified gold nanoparticles (PATP‐AuNPs) were used as colorimetric and Surface Enhanced Raman Scattering (SERS) probes for the sensitive detection of Escherichia coliDH5 α, as a model for Gram‐negative bacteria. The nano‐probes were easy to prepare through Au‐S bonding. Under optimized conditions, the PATP‐AuNPs surface with positive charge can bind with negatively charged E.coliDH5 α via electrostatic adhesion, resulting in a quick color change from red to blue, and also a dramatic SERS signal enhancement from thousands of AuNPs aggregated on the surface of bacteria, which was utilized for both colorimetric and SERS detection of E.coliDH5 α. For colorimetric analysis, it is the first time that the classical partial least square (PLS) regression was utilized to deal with the relationship between adsorption and E.coliDH5 α concentrations. Excellent linear relationship was observed from 1.1 x 10 7 to 1.3 x 10 8 cfu mL ‐1 with the average relative error (ARE) of 5.430, which was more accurate than the traditional extinction ration method. When coupled with confocal Raman microscope, this PATP‐AuNPs probes could be used to detection SERS signals produced from even one single bacterium. This bioassay is rapid, less expensive and convenient for bacteria detection and analysis. Therefore, PATP‐AuNPs system as a novel, versatile, on‐site and real‐time Gram‐negative bacteria sensor, would have a wide range of practical applications.