Study of the Biological Glutathione in Algae by Established Quantum Dot Covalent Coupling System

Abstract

Quantum dot materials had obvious advantages over traditional fluorescent materials for their broad excitation and narrow emission spectra, signal brightness, high quantum yield, and light stability. To research the low concentration component in the biology, water-soluble carbon quantum dots (CQD) were explored to be used as probes to detect biomolecule glutathione (GSH) in algae. The surface of CQD was functionally modified. The influence of the amount of carbodiimide, C8HN3 (EDC), the amount of NHS, pH, reaction time, on the coupling reaction was investigated in the GSH detection process. In actual biological systems, using CQDs to detect GSH had good immunity. It was highly selective when other interfering substances existed. EDC combined with NHS (N-hydroxysuccinimide) improved coupling efficiency. The efficiency of the reaction was improved by stabilizing the O-acyl isothiourea intermediate. Covalently coupling biomolecules with water-soluble quantum dots had rapid and sensitive detection performance. At pH of 7 and reaction time of 20 min, the calibration curve was got as: (F-F0)/F0=0.05994+0.03741C. Stably covalent coupling CQDs was expected to become an innovative method for qualitative and quantitative analysis of biomolecules GSH.