Flexible nanoplasmonic sensor for multiplexed and rapid quantitative food safety analysis with a thousand-times sensitivity improvement.

The accumulation of trace amounts of certain small molecules in food poses considerable human health challenges, including the potential for carcinogenesis and mutagenesis. Here, an ultrasensitive gold-platinum nanoflower-coupled metasurface plasmon resonance (MetaSPR) (APNMSPR) biosensor, based on a competitive immunoassay, was developed for the multiplexed and rapid quantitative analysis of trace small molecules in eggs, offering timely monitoring of food safety. This one-step biosensor can be integrated into either a newly designed detachable high-throughput MetaSPR chip-strip plate device or a standard 96-well plate for multiplexed small-molecule detection within a single egg. The limits of detection were 0.81, 1.12, and 1.74 ppt for florfenicol, fipronil, and enrofloxacin, respectively, demonstrating up to 1000-fold increased sensitivity and a 15-fold reduction in analysis time compared with those of traditional methods. The results obtained using the APNMSPR biosensor showed a strong correlation with those obtained using liquid chromatography-tandem mass spectrometry. The APNMSPR biosensor holds immense promise for the multiplexed, highly sensitive, and rapid quantitative analysis of small molecules for applications in food safety control, early diagnosis, and environmental monitoring.