Anthrapyrazolone functionalized Oligo(ethylene glycol)methyl ether methacrylates based fluorescent polymeric hydrogel for selective detection of Tetracycline drug

Tetracycline (TC) antibiotics are essential for treating bacterial infections; however, overuse and improper disposal place the environment in danger and promote the growth of drug-resistant microorganisms. Monitoring their impact on living organisms is vital. Polymeric-based hydrogels offer promise in antibiotic detection due to their versatility and biocompatibility, despite their uncommon use for this purpose. In this study, we have synthesized a fluorescent polymeric hydrogel, P(OEGMA-co-DIMA) utilizing oligo(ethylene glycol)methyl ether methacrylates (OEGMA) and laboratory-synthesized fluorescent anthrapyrazolone containing monomer, 2-(benzo[1,2,3-cd:4,5,6-c’d]bis(indazole)-2(7H)-yl)ethyl methacrylate (DIMA) for the fluorometric detection of TC in the aqueous medium. The P(OEGMA-co-DIMA) hydrogel exhibited exceptional affinity towards TC while exhibiting high selectivity. The chemosensing behavior of the hydrogel was also compared with the DIMA monomer. Upon adding TC, emission analysis revealed a notable quenching in the emission intensity of the P(OEGMA-co-DIMA) hydrogel as well as the DIMA monomer. The Stern Volmer rate constants (Ksv) of the hydrogel (Ksv = 9.99 x 103 M−1) in water and DIMA (Ksv = 25.63 x 103 M−1) in acetonitrile showed a higher quenching rate constant with a limit of detections (LODs) of 1.3 nM and 0.11 nM. Turn-off fluorescence behavior occurs via a static quenching mechanism through a photoinduced electron transfer process and intermolecular hydrogen bonding. To validate the selectivity, the interference analyses in an aqueous medium with different antibiotics are provided. To rationalize the real-time applicability of the hydrogel, studies were extended to water samples obtained from deionized water, tap water, lake water, and also in milk samples. The recovery rate and LOD for real samples ranged from 83.8 % to 111 % and 0.83 to 3.6 nM, respectively.