A Nanobiomimetic Neural Memcapacitor Serves as a Voltage Sensor and an Amperometry Sensor for Reagent-less Direct Detection of Sub pM Soluble Amyloid-β

摘要

Challenges of quantitative detection of Amyloid-beta (AP) in Alzheimer's brains are paramount, such as the instability of soluble Aβ_(1-42) in biological specimens, the interferences among proteins and the time consuming assays. A memcapacitor device was developed with nanostructured biomimetic acetylcholinesterase (ACHE) gorge membrane on gold chips, served as an artificial normal brain motif, has detected voltage and current changes in sub pM Aβ under conditions of free from antibodies and tracers using spiked NIST SRM 965A human serum, based on the characteristics of memcapacitor/memristor. The results of Detection of Limits (DOL) are 5.0×10~(-11)M/cm~2 vs. 7.0×10~(-13)M/cm~3 over the linear range at 0.04-151 nM vs. 3.8-471 nM, for the chronoamperometry (CA) and double step chronopotentiometry (DSCPO) methods, respectively. Aβ-spiked fresh human capillary whole blood (CPWB) specimens used to verify the accuracy were traceable to NIST standards with recoveries of 100.15± 1.2% and 98.6±1.1% and the imprecision results are 3.2% vs. 6.0% (n=18, n=15) for CA and DSCPO method, respectively. The results of the signal to noise ratio for both methods are about 12.