Design and preparation of poly(tannic acid) nanoparticles with intrinsic fluorescence: A sensitive detector of picric acid

Novel fluorescent poly(tannic acid) nanoparticles (FPTA NPs) were successfully synthesized via the self-polymerization reaction of tannic acid (TA) being followed by the degradation with hydrogen peroxide (H2O2). The as-prepared FPTA NPs possessed excellent intrinsic fluorescence characteristics as well as the features of low-cost, good biodegradation, convenient and large-scale preparation. It was found that picric acid (PA) could act as a strong quencher for FPTA NPs. Subsequently, the FPTA NPs-based fluorescent sensor was used for PA detection, which showed a sensitive and fast response towards PA. The utilizations of TA are mainly in the field of surface modification, and this work is the first report on utilizing the autofluorescence characteristics of FPTA NPs in sensor development, which will further broaden the application of TA. The method is of profound meanings for the excellent sensitivity and selectivity and low cost from the engineering viewpoint.