Self-Assembled Glycobisacrylamide-Stabilized Gold Nanoparticles for Fluorescent turn-on Sensing of Lectin and Escherichia Coli

Gold nanoparticles with shelf life more than six months at 25 °C were synthesized by in-situ reduction and stabilization using a D-glucose based bisacrylamide solution. TEM images support the homogeneous coating of Au nanoparticles by Glc-bis. In the process intrinsic emission of self assembled glycobisacrylamide (Glc-bis) was quenched by AuNPs and the resultant system, Glc-bis@AuNPs, can work as a turn-on sensor, wherein the quenched emission was restored upon addition of lectin, Concanavalin A (Con A). The aggregation of Glc-bis@AuNPs upon interaction with Con A was pragmatic from the TEM images. The quenching as well as recovery of emission based on the proximity of AuNPs with Glc-bis in Glc-bis@AuNPs was further confirmed by steady state as well as fluorescence lifetime measurements. The Glc-bis@AuNPs system was found to be stable upto 1 M NaCl concentration, a factor that fulfills the requirement for bio-sensing applications. The binding constant of Glc-bis@AuNPs towards Con A was 9.8 × 104 M-1 whils...