Process for preparing high-performance sensing film of fluorescent sensor by covalently immobilizing indicator dye

Abstract

The invention discloses a process for preparing a high-performance sensing film of a fluorescent sensor by covalently immobilizing an indicator dye. The process comprises the following steps: cleaning a quartz glass plate sequentially with 3% HF acid, 10% H2O2 and distilled water; introducing thiohydroxy on the surface of the cleaned glass plate by (3-mercaptopropyl)trimethoxysilane (MPS); self-assembling the glass plate with the thiohydroxy in gold nanoparticle colloidal solution for 12-24h (preferred 15h) and fixing the gold nanoparticles on the glass plate; immersing the glass plate on which the gold nanoparticles are fixed in ethanol solution of (1.0-5.0)*10<-3>mol L<-1> (preferred 2.0*10<-3>mol L<-1>) mercapto carboxylic acid for 10-18h (preferred 12h), introducing long carbon chains and carboxyl on the surfaces of the gold nanoparticles, wherein, the carbon chain of the adopted mercapto carboxylic acid comprises preferably 10-16 carbon atoms; activating the carboxyl on the surfaces of the gold nanoparticles with 1-ethyl-3-(3-dimethylamino propyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS); and immersing the glass plate on which the carboxyl is activated in acetone solution (2.0*10<-4>-5.0*10<-3>mol L<-1> of the indicator dye RNH2 with primary amido, preferred 1.0*10<-3>mol L<-1>) for 4.0-9.0h (preferred 6h), then the indicator dye is covalently immobilized on the outmost layer of the glass plate to form the ultrathin sensing film, then preparing the fluorescent sensor with the covalently immobilized indicator dye. The sensing film of the sensor has the advantages of no dye loss, quick response (response time is less than 2s), easy regeneration and good reversibility when in use.

Description

technical field [0001] The invention relates to the preparation of a sensitive film of a fluorescent chemical sensor, in particular to a process for covalently fixing a fluorescent indicator dye on a quartz glass slide to form an ultra-thin sensitive film by using a covalent bonding method. Background technique [0002] Fluorescent chemical sensors are simple, fast, sensitive, and suitable for long-distance measurement, and have broad application prospects in clinical diagnosis, biological analysis, and environmental monitoring. The key to the preparation of fluorescent chemical sensors is how to fix the fluorescent indicator dyes on the support material to form a strong sensitive film. The immobilization method of the indicator dye plays a decisive role in the life, reversibility, reproducibility, response time, leakage resistance and photobleaching resistance of the prepared sensor. According to literature reports, the fixation methods of indicator dyes include physical e...

AI Technical Summary

Problems solved by technology

Some researchers at home and abroad have made some attempts in this regard, choosing quartz glass slides as carriers, covalently immobilizing fluorescent indicator dyes on the slides with ultraviolet light polymerization technology, and making some photochemical sensors, the dyes of which are hardly lost, but The thickness of the prepared sensor sensitive film is not suitable for control, the response of the film is slow, reversible, and the reproducibility is not ideal

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