Ultrafast one-pot microwave-assisted green synthesis of silver nanoparticles from Piper longum fruit extract as a sensitive fluorescent nanoprobe for carbamazepine and risperidone in dosage forms and human plasma

Abstract

A rapid, simple, and green method was developed for the synthesis of highly fluorescent silver nanoparticles (Ag-NPs) using a microwave-assisted synthetic approach in about 30 sec. The developed method used the extract of Piper longum fruit as a reducing agent. Characterization of the obtained Ag-NPs was performed using various microscopic and spectroscopic techniques. The prepared Ag-NPs were applied as a fluorescent probe for the spectrofluorimetric determination of each of carbamazepine (CBZ) and risperidone (RIS). The developed Ag-NPs exhibited a strong emission peak at 354 nm when excited at 265 nm. The mean size of Ag-NPs was found to be 27.3 nm with a polydispersity of 0.351. The developed method is the first spectrofluorimetric method that uses Ag-NPs to determine CBZ or RIS and the only spectrofluorimetric one for RIS determination. Ag-NPs native fluorescence was found to be quantitatively and selectively quenched by both drugs, and method validation exhibited a linear relationship in the range of 20.0–120.0 µM and 5.0–100.0 µM with detection limits of 1.47 µM and 0.84 µM for CBZ and RIS, respectively. The quenching mechanism of Ag-NPs native fluorescence by each CBZ and RIS was studied. The proposed method was then applied to determine CBZ and RIS in their pharmaceutical dosage forms and human plasma samples with high % recoveries and low % RSD. Furthermore, the synthesized Ag-NPs showed noteworthy antimicrobial activities against four different bacterial strains and one species of candida. As a result, the proposed method may have potential uses in antimicrobial therapy and the study of related mechanisms. The greenness of the proposed method was evaluated using two different greenness metric tools, including the complementary green analytical procedure index (Complex GAPI) and Analytical GREEnness (AGREE). Validation of the proposed approach was carried out according to ICH guidelines.