Label-free detection of creatinine using nitrogen-passivated fluorescent carbon dots

摘要: In the field of biochemistry and biosensing, passivation carbon dots using nitrogen dopants has attracted great attention, as this can control their photoluminescence (PL) properties quantum yield. To date, in fabrication a sensing probe, impact chemical composition passivating molecule remained unexplored. work, we chose series different nitrogen-rich precursors (such urea, thiourea, cysteine, glycine) ascorbic acid to synthesize nitrogen-doped (NCDs). A significant change surface states was obtained due evolution variable contents amino, pyridinic pyrrolic species, which is evident from X-ray photoelectron spectroscopy, leads an increment PL yields (PLQY ∼ 58%) average lifetime values. Spectroscopic analysis revealed that rise ratio pyrrolic : amino groups on cause bathochromic shift generate excitation-dependent NCDs. Besides, these NCDs were used fluorescence off–on probes, where PA-infested NCD solution detect creatinine. Chiefly, restoration achieved formation Jaffe chromogen between creatinine PA. However, all nitrogen-passivated dot surfaces do not respond similarly towards only non-amino-rich exhibit maximum (50%) turn-on response. The turn-off–on methodology showed satisfactory good linearity range 0 150 μM with detection limit 0.021 nM for Three input molecular logic gates also designed based response NCDs@PA Additionally, analytical method validation, real-sample performed creatinine, recoveries (93–102%) verified tailored physicochemical enhanced ability.