Method for measuring kinetic and thermodynamic parameters on solid-liquid interface

Abstract

The invention discloses a method for measuring kinetic and thermodynamic parameters on a solid-liquid interface, which comprises the steps of according to frequency-time curve graphs corresponding to various ligand solutions with different concentrations to be measured and frequency-time curve graphs of another ligand solution with the concentration to be measured at two different temperatures, analyzing and calculating an output frequency-time curve of a micro-cantilever sensor to obtain dynamic and thermodynamic parameters (the binding / dissociation equilibrium constant KA / KD, the Gibbs free energy [delta]G degree, the surface coverage [theta], the binding / dissociation rate constant ka / kd and the reaction activation energy Ea) of a nucleic acid aptamer and a ligand thereof on the solid-liquid interface. The method overcomes the defects that a traditional method is expensive in instrument, tedious in operation, single in parameter determination and the like, has the advantages of being high in sensitivity, low in cost, simple and rapid in operation, free of marking and correction, capable of effectively avoiding system errors, capable of determining related parameters at a time and the like, and is suitable for determination of dynamic and thermodynamic parameters of multiple nucleic acid aptamers and ligands thereof.

Description

technical field [0001] The invention relates to the technical field of molecular dynamics / thermodynamics, in particular to a method for measuring kinetics and thermodynamic parameters of biochemical reactions on a solid-liquid interface. Background technique [0002] Nucleic acid aptamer (Nucleic Acid Aptamer) is a synthetic RNA or DNA receptor molecule, a variety of target substances (small molecules, proteins and even cells) can be their ligands. Aptamers have become a common molecular recognition element in the development and application of biosensors due to their stable chemical properties, easy synthesis, and can be modified according to requirements, and have high specificity and affinity for their ligands. . [0003] When a biosensor is used to detect the analyte in the solution, no matter the reaction, energy transfer, or signal conversion, the place where it occurs is the solid-liquid interface. Therefore, quantitative studies on the kinetics / thermodynamics of bi...

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Problems solved by technology

Although a lot of work has been done to study the kinetics and thermodynamic behaviors of nucleic acid aptamers and their ligands in solution, due to the diffusion layer on the solid-liquid interface and the steric hindrance effect of the capture probes, there will be energy barriers. The parameters cannot describe the kinetics and thermodynamics of biochemical reactions on the interface; the existing methods for studying the kinetics and thermodynamics of solid-liquid interfaces are often limited by factors such as signal labels and temperature ranges. Therefore, the development of bio-interface sensing, especially It is a biosensing system based on the reaction between nucleic acid aptamers and ligands. It is urgent to provide a method for quickly measuring the kinetics and thermodynamic parameters of nucleic acid aptamers and ligands on the solid-liquid interface, so as to systematically study solid-liquid Dynamics and thermodynamics mechanisms and physical and chemical processes at the interface

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