ZnS@ fluorenone derived multifunctional quantum dots for simultaneous recognition of bovine serum albumin (BSA) and copper ions (Cu2+) in aqueous blood and urine samples

An efficient synthesis of water-stable and fluorescent ZnS quantum dots has been executed beginning with its organic predecessor possessing fluorenone for sensing bovine serum albumin (BSA) among other proteins. Moreover, the organic predecessor of quantum dots has also been utilized for sensing of F- ions with binding constant of 1.8 x 104 M-1. Various spectroscopic techniques such as high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (PXRD), UV-visible (UV-vis), Fourier transform infrared (FTIR), thermogravimetric (TGA), Energy dispersive X-ray analysis (EDX), circular dichroism (CD) and Fluorescence (FL) spectroscopy have been utilized for the characterization of the developed quantum dots. The emission properties of quantum dots made them useful for the sensing of BSA and Cu2+ accompanied with secondary sensing of urea. The LODs value for BSA and Cu2+ were calculated as 213 and 211 nM, respectively. Demonstrating remarkable efficacy, these quantum dots have been successfully employed for the discernment of BSA in human blood and urine samples, achieving an outstanding recovery rate of up to 99.8%.