A Facile Colorimetric and Spectrophotometric Method for Sensitive Determination of Metformin in Human Serum Based on Citrate-Capped Gold Nanoparticles: Central Composite Design Optimization

Abstract

For the determination of Metformin in human serum, a facile colorimetric and spectrophotometric sensor was designed based on citrate-capped gold nanoparticles (citrate-GNPs). In this probe, the addition of Metformin to GNP solution generates a naked-eye color change resulting from the aggregation of GNPs. Study of this color conversion and quantity analysis of analyte is operated by spectrophotometric instruments. The three factors pH, time, and GNP ratio were selected to examine their effects on sensing results and their values optimization. The optimization of parameters was done by means of central composite design and one-at-a-time methods. The sensing results proved the highly selective and sensitive performance of the sensor for Metformin in a linear range of 6.25–133.3 ppm with a detection limit of 1.79 ppm. The relative standard deviation (RSD) of the reported method is 2.53%.

Graphitic Carbon Nitride Quantum Dots in Dual-Mode Fluorescence Switching Platforms for Trace Analysis of Ag(I) and l-Cysteine

“…Shuang’s group designed an anthraquinone–imidazole-based colorimetric and fluorescent sensor for the analysis of Ag­(I) and thiols . Zare-Dorabei’s groups synthesized diphenylthiocarbazone immobilized on the triacetyl cellulose membrane, a nanocomposite containing silver sulfide QDs and graphitic carbon nitride nanosheets (g-C 3 N 4 NNs), and a series of nanomaterials to detect Ag­(I), small biological molecules, and other hazardous substances. − Liao’s group prepared the g-C 3 N 4 NNs/polyacrylamide/polyacrylic acid composite hydrogel by using the radical polymerization method, which can act as a fluorescent probe to detect Ag­(I) with a limit of detection (LOD) of 6.31 μmol L –1 . Chen’s group synthesized the acetaldehyde-modified g-C 3 N 4 NNs through the ethylene glycol-assisted liquid exfoliation method, which was successfully used to detect Ag­(I) based on the photo-induced electron transfer (PET) .…”

Exploiting the Catalytic Ability of Polydopamine-Remodeling Gold Nanoparticles toward the Naked-Eye Detection of Cancer Cells at a Single-Cell Level

“…In this study, we exploited the intrinsic catalytic property of gold nanoparticles (AuNPs) on the reduction of blue methylene blue (MB) to colorless leuco-MB (LMB), creating a colorimetric sensing strategy. − Although target-induced aggregation of AuNPs is a commonly applied strategy for constructing a sensing platform based on the color difference between the wine red, well-dispersed AuNPs, and the dark purple, aggregated AuNPs. However, the color differentiation between the two colors can be subjective among different observers and yet can pose a limitation on detection sensitivity.…”

Citrate capped silver nanoparticles as an instantaneous colorimetric selective sensor for neomycin and thiamine in wastewater

“…Furthermore, it is expected that the -NH 2 group and sulphur atom present in thiamine tend to form noncovalent bonds with the -COOH groups of AgNPs. 51 The intensity of the transmittance peaks at 1559 cm À1 and 1375 cm À1 for the carboxylate groups decreased after neomycin and thiamine treatment which dictates the possibilities for involvement in hydrogen bonding with -COO functionalities. The peak of AgNPs centered at 1060 cm À1 shifted to 1135 cm À1 after the addition of neomycin, which further indicates the hydrogen bonding between carboxylic acid and amine/alcohol groups.…”