In-situ microscale spectrophotometric determination of phenytoin by using branched gold nanoparticles.

Abstract

A rapid method for the sensitive detection of phenytoin (PHT) by branched gold nanoparticles (B-AuNPs) is described. These nanoparticles were synthesized by adding methanol as the reducing agent and poly(ethylene glycol) as the stabilizer at 70°C. The B-AuNPs are red in color with an absorption maximum at 540nm when prepared in situ. However, the color becomes increasingly weaker when PHT is present in increasing concentrations. This method can determine PHT over the 67-670ng·mL-1 concentration range, with detection limit of 21ng·mL-1. The relative standard deviation for five replicate measurements at 68 and 530ng·mL-1 of PHT was 3.2% and 1.2%, respectively. The method was applied to thedetermination of PHT in plasma samples of epileptic patients, and theresults were in agreement with those obtained by a standard official method. Graphical abstract Branched gold nanoparticles (AuNPs) prepared in situ have a red color with an absorption maximum at 540nm. The color becomes increasingly weaker with decreasing the intensity of the characteristic SPR band when PHT is present in increasing concentration. The current assay is capable of determining PHT over the 67-670ng·mL-1 concentration range with a limit of detection of 21ng·mL-1.