S-H. Duh, J. Thornton, P.T. Kissinger, E.T. Chen
Advanced Biomimetic Sensors, Inc., United States
pp. 172 - 175
Keywords: nanobiomimetic neuronal memcapacitor, voltage sensor and amperometric sensor, reagent-less
Amyloid-beta (A) plaque accumulation in the brain has been recognized to be associated with Alzheimer’s and dementia. Challenges of quantitation of Ab are the instability of soluble Ab1-42 and the protein interference plus the time consuming assays. We developed a nanostructured biomimetic sensor serving two functions: detecting voltage and current of Ab concentrations under the conditions of direct measurement and free from antibody and tracers. The characteristics of memcapacitor/memristor were observed in the i-V curves of the hysteresis. The double step chronopotentiometry (DSCPO) method measured discharge pulse energy change with a minimum 5.0 aWHr at 3.8 nM Ab over 0.25-333 Hz; The chronoamperometry (CA) method measured a minimum current change of 1.7 nA at 0.04 nM. Both methods have a mean S/N =12. The values of Detection of Limits (DOL) are 5.0x10-11 vs. 7.0x10-13M for the CA and DSCPO method over the linear range at 0.04-151 nM vs. 3.8-471 nM per cm2 and cm3, respectively. Ab spiked fresh human capillary whole blood (CPWB) specimens (n=18, n=15) were measured without a stabilizer for each of the two methods with the Pooled RSD of 3.2% vs. 6.0% over the studied range for the CA and the DSCPO method, respectively.