Fluorescence Turn-off Sensor for Selective Determination of Nimesulide Based on Protein Functionalized Gold Nanoclusters

Fluorescence sensing is a highly sensitive detecting method realized through producing an attenuation, enhancement or wavelength shift in the emission. Protein conjugated fluorescent gold nanoclusters (NCs) owe much attention in the field of medical and nanobiotechnology due to their intense and versatile photo stability characteristics. Herein we present a nanosensor with fluorometric readout based on protein-stabilized gold nanoclusters for the selective sensing of the non-steroidal anti-inflammatory drug Nimesulide (NIM). NIM induced a photoluminescence (PL) quenching of BSA-modified gold nanoclusters via an electron transfer mechanism and a novel turn-off sensor was developed. The quenching of fluorescence intensity of BSA stabilised gold nanoclusters allowed the selective determination of NIM in the linear range 1.0 × 10-4 – 5.0 × 10-6 M and a limit of detection (LOD) of 6.28 × 10-7 M was obtained. More importantly the developed sensor allowed precise determination of NIM in commercially available pharmaceutical formulations.