A Reusable Chronocoulometric Aptamer Sensor for Detection of Adenosine Triphosphate / 分析化学

ABSTRACT

A reusable chronocoulometric adenosine triphosphate (ATP)-aptamer sensor was developed in this work.A short chain of DNA marked as cDNA containing complementary sequence was immobilized on gold electrode based on Au-S self-assembly.The ATP aptamer was hybridized with cDNA.The surface-confined DNA could bind with [Ru(NH3)63+ (RuHex) in the electrolyte via electrostatic interaction.Upon target ATP binding, the aptamer confined onto electrode surface was disassociated from the cDNA oligonucleotides into the solution.Such surface density change of DNA lead to the decrease of chronocoulometric signal for the RuHex which confined on the electrode surface.The chronocoulometric signals showed a linear relationship with logrithm of ATP concentration in the range of 1 nmol/L to 100 μmol/L, and the detection limit of this aptamer sensor could reach 0.5 nmol/L (S/N=3).This aptamer sensor could be regenerated 5 times by simple steps.With this aptamer sensor, the basal level of ATP in the brain cortex micorodialysate was determined to be 19.2±3.7 nmol/L (n=3).