Signal-amplifying nanoparticle/hydrogel hybrid microarray biosensor for metal-enhanced fluorescence detection of organophosphorus compounds. (16th March 2018)

• Record Type: Journal Article
• Authors: Kim, Minsu; Kwon, Ji Eon; Lee, Kangwon; Koh, Won-Gun
• Is Part Of: Biofabrication. Volume 10:Number 3(2018)
• Publication Date: 2018-03-16
• Subjects: paraoxon biosensor -- metal-enhanced fluorescence -- hydrogel microarray -- quantum dots -- silica-coated silver nanoparticles; Biomedical engineering -- Periodicals; Tissue engineering -- Periodicals; Biomedical materials -- Microstructure -- Periodicals; Bioengineering -- Periodicals; 610.28
• DOI: 10.1088/1758-5090/aab004
• Languages: English
• ISSNs: 1758-5082

Abstract

Abstract: In this study, we developed an enzyme-based miniaturized fluorescence biosensor to detect paraoxon, one of the most well-known neurotoxic organophosphorus compounds. The biosensor was fabricated with poly(ethylene glycol) (PEG) hydrogel microarrays that entrapped acetylcholinesterase (AChE) and quantum dots (QDs) as fluorescence reporters. Metal-enhanced fluorescence (MEF) was utilized to amplify the fluorescence signal, which was achieved by decorating QDs on the surface of silica-coated silver nanoparticles (Ag@Silica). The MEF effects of Ag@Silica were optimized by tuning the thickness of the silica shells, and under the optimized conditions, the fluorescence intensity was shown to be increased 5 fold, compared with the system without MEF. PEG hydrogel microarray entrapping QD-decorated Ag@Silica and AChE was prepared via photopatterning process. The entrapped AChE hydrolyzed paraoxon to produce p-nitrophenol within the hydrogel microstructure, which subsequently quenched the fluorescence of the QDs on the surface of Ag@Silica. The MEF-assisted fluorescence detection resulted in a significant enhancement of paraoxon detection. The detection limit was approximately 1.0 × 10 −10 M and 2.0 × 10 −7 M for sensing with and without MEF, respectively. The successful integration of a hydrogel microarray system with a microfluidic system was demonstrated to be a potential application for the MEF-based micro-total-analysis-system.