Selective detection of azelnidipine in pharmaceuticals via carbon dot mediated spectrofluorimetric method: A green approach

Abstract

A spectrofluorimetric method using fluorescent carbon dots (CDs) was developed for the selective detection of azelnidipine (AZEL) pharmaceutical in the presence of other drugs. In this study, N‐doped CDs (N‐CDs) were synthesized through a single‐step hydrothermal process, using citric acid and urea as precursor materials. The prepared N‐CDs showed a highly intense blue fluorescence emission at 447 nm, with a photoluminescence quantum yield of ~21.15% and a fluorescence lifetime of 0.47 ns. The N‐CDs showed selective fluorescence quenching in the presence of all three antihypertensive drugs, which was used as a successful detection platform for the analysis of AZEL. The photophysical properties, UV–vis light absorbance, fluorescence emission, and lifetime measurements support the interaction between N‐CDs and AZEL, leading to fluorescence quenching of N‐CDs as a result of ground‐state complex formation followed by a static fluorescence quenching phenomenon. The detection platform showed linearity in the range 10–200 μg/ml (R2 = 0.9837). The developed method was effectively utilized for the quantitative analysis of AZEL in commercially available pharmaceutical tablets, yielding results that closely align with those obtained from the standard method (UV spectroscopy). With a score of 0.76 on the ‘Analytical GREEnness (AGREE)’ scale, the developed analytical method, incorporating 12 distinct green analytical chemistry components, stands out as an important technique for estimating AZEL.

Sensitive and rapid determination of tetracycline antibiotic by carrot juice‐derived carbon dots as a fluorescent probe

“…The surfaces of the obtained CDs were highly covered with basic elements of carrot juice in the form of hydroxyl, carboxyl, and nitrogen-containing groups without further modification; thus, the CDs are negatively charged in aqueous media [24,25], and can act as electron donors and acceptors [26]. Additionally, the obtained CDs displayed superior aqueous stability and maintained a stable fluorescence intensity against different changes, making them promising for probing and sensing applications [27].…”

“…Certain interactions are expected to occur between the CDs probe and TC molecules (such as hydrogen bonding), resulting in aggregation and subsequent quenching of the probe's fluorescence as reported in [6]; such interactions contributed to the energy of carrot juice-derived carbon dots (CJ-CDs) captured by forming new bonds [4], triggering a sensitive response of the surface functional groups of CJ-CDs to the target analyte [27].…”