A Co-Doped Carbon Dot/Silver Nanoparticle Nanocomposite-Based Fluorescence Sensor for Metformin Hydrochloride Detection

Abstract

In this study, a fluorescence sensor based on nitrogen and phosphorus co-doped carbon dot/silver nanoparticle (NPCD/AgNP) nanocomposites was developed for metformin hydrochloride (MFH) detection. We first utilized the reducing nature of the NPCDs to prepare AgNPs from Ag+ and subsequently prepare NPCD/AgNP nanocomposites. The nanocomposite material was characterized by various methods, including electron microscopic methods (SEM and TEM), spectroscopic methods (UV-Vis, PL, FTIR, and XPS spectroscopy), light scattering (ELS), and XRD. Further, we utilized the enhanced fluorescence of the NPCDs as well as the overlap between the fluorescence emission spectrum of the NPCDs and the absorption spectrum of the AgNPs to use the NPCD/AgNP nanocomposites as an effective inner filter effect (IFE) pair for sensing MFH. The IFE between NPCDs and AgNPs in the nanocomposite material resulted in a significant quenching of the fluorescence intensity of the nanocomposites compared to that of the pure NPCDs. However, the fluorescence was recovered when MFH was introduced into the nanocomposite solution. The fluorescence intensity of the nanocomposites increased linearly as the MFH concentration increased from 2 to 100 µg/L. This detection method showed good sensitivity compared to other methods. It also showed high selectivity and high sensing potential for MFH in human serum and yielded acceptable results.

Luminescence of carbon quantum dots and their application in biochemistry

“…These attributes position them as a promising contender across a spectrum of applications. Because CDs have luminescent properties similar to semiconductor quantum dots [ [16] , [17] , [18] ], resulting in their application across diverse domains, encompassing biomedicine [ 19 ], catalysis, optoelectronic devices and anti-counterfeiting [ 20 , 21 ].…”

Functional Nanomaterials for Sensing and Detection

“…In another contribution, J. Borges et al developed a plasmonic Au-TiO 2 thin film and demonstrated its potential use as an LSPR platform for label-free biosensors [ 6 ]. Fluorescence-based detection is one of main sensing techniques, and S. J Park et al fabricated a nitrogen and phosphorus co-doped carbon dot/silver nanoparticle nanocomposite for a fluorescence sensor, which could sensitively detect metformin hydrochloride with high selectivity [ 7 ]. Efficient pH detection is important in chemical syntheses.…”