The dual-mode platform based on cysteamine-stabilized gold nanoparticles for the high throughput and on-site detection of bongkrekic acid

This article describes the visual detection of bongkrekic acid (BA) by cysteamine modified gold nanoparticles (CS-AuNPs) as colorimetric probes. Polycarboxyl structured BA induces the aggregation of CS-AuNPs through electrostatic interaction, which results in the color change of CS-AuNPs from wine-red to blue-violet. The ratio of absorbance at 650 nm and 524 nm (A650/A524) increases linearly in the 0.18–1.64 μM BA concentration range, and the detection limit is 3.43 nM. Moreover, when combined with solid phase extraction (SPE), the method can also be used for specific detection of BA in complex food matrix (tremella). The recoveries in urine, serum, and tremella ranged from 89.31% to 109.63%. Interestingly, a smartphone application (APP) was applied to identify the R, G, and B values of the solution, and the quantitative curve was established by calculating the gray value. This approach was then used to quantify the BA in the sample solution. The linear range of APP detecting is 0.10 μM–1.44 μM and the detection limit is 12.33 nM. This method can be used not only for food safety monitoring, but also for preliminary clinical screening of BA poisoning.