Metal carbonyl-gold nanoparticle conjugates for highly sensitive SERS detection of organophosphorus pesticides

Publication date: 15 October 2017
Source:Biosensors and Bioelectronics, Volume 96
Author(s): Mein Jin Tan, Zi-Yao Hong, Mei-Hua Chang, Chih-Chen Liu, Hwei-Fang Cheng, Xian Jun Loh, Ching-Hsiang Chen, Chia-Ding Liao, Kien Voon Kong
The binding of organometallic osmium carbonyl clusters onto the surface of gold nanoparticles (^10OsCO-Au NPs) greatly enhanced the CO stretching vibration signal at ~2100cm⁻¹, which is relatively free from interference due to the absorbance of biomolecules. By utilizing the acetylcholinesterase (AChE) mediated hydrolysis of acetylthiocholine to thiocholine where the activity of AChE is inhibited by the presence of organophosphate pesticides (OPPs), the subsequent thiocholine-induced aggregation of ^10OsCO-Au NPs can be monitored by the change in color of the NPs solution and the variation in intensity of the SERS CO signal. The change in color offers a fast pre-screening method, whereas monitoring via SERS is used for greater accuracy and lower limit of detection (0.1 ppb) for quantitative detection. Its potential as a quick and accurate method of OPPs monitoring in consumer products was demonstrated in the detection of OPPs in real spiked samples such as beer.



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