Molecular recognition-driven fluorescence quenching based sensing of ascorbic acid using a β-cyclodextrin/graphene oxide-TMB fluorescent probe.

This study reports the development of β-CD/GO and TMB based fluorescent sensing system synthesized via a facile hydrothermal approach for sensitive detection of ascorbic acid (AA) in food matrices. The structural and surface characteristics of such nanohybrid were confirmed by XRD, FTIR, Raman, zeta potential, and particle size analysis, while microscopic investigations revealed uniform surface modification of the nanosheets. In analytical studies, a fluorescence quenching based sensing mechanistic system was demonstrated through host guest molecular recognition and photoinduced electron transfer (PET) upon the introduction of AA. The synergistic integration of GO, and host guest recognition capability of β-CD, along with its strong quenching efficiency, enabled precise detection of AA. Under the optimized conditions, the sensor exhibited a linear response over the concentration range of 2.5-40 μM, with a detection limit of 1.21 μM. Furthermore, the developed probe was successfully applied to real food samples, including lemon, mango, and orange juices with recoveries of 92.3-106.4%. Overall, this work presents a rapid, cost-effective, and portable fluorescence-based strategy for practical food safety analysis.