Sulfonamide Fluorescent Probe Applied in Live Cell Imaging, LFPs, and Electrochemical Sensor

Abstract

New sulfapyridone azo fluorescent probes (SPAFP) have been developed for the imaging of live cells. Rapid access to this novel class of DMSO-soluble fluorophores was made possible through an electrophilic substitution reaction. The synthesized molecule was confirmed by HRMS, FT-IR, ¹H NMR, ¹³C NMR, UV–vis, and PL-emission. Density functional theory (DFT) at the B3LYP/6-31G-IEF-PCM method and HOMO-LUMO energy analysis were employed. The detection mechanism is based on the azo bond that shows fluorescence (λ_emi 766 nm). Extensive study of latent fingerprints (LFPs) identified permanent, unalterable, and unique pores separated across the surfaces by revealing level 1–3 ridge features upon exposure to UV light at 365 nm, which highlights ridges. The SPAFP is active with cytotoxicity. The novel electrochemical sensor for dopamine (DA) was developed using the SPAFP-modified glassy carbon electrode (SPAFP/MGCE), which exhibited enhanced electrocatalytic behavior for individual detection of dopamine (DA) in supporting electrolyte (PBS 7.0) by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. At SPAFP/MGCE, the scan rate variation investigation indicates that the overall electrode process is diffusion-controlled kinetics for DA. This fabricated sensor exhibited a lower detection limit (LOD) of 2.5 nM (S/N = 3) with a linear range of 0.01–5.5 μM for DA detection.