Screening-Limited Response of NanoBiosensors

TL;DR

This paper develops a theoretical framework combining Poisson-Boltzmann and reaction-diffusion equations to explain the logarithmic response of nanoBiosensors to various factors, clarifying previously puzzling experimental results.

Contribution

It introduces a unified analytical model that explains the sensor response behavior based on electrostatic and kinetic principles, addressing gaps in existing theories.

Findings

Sensor response varies logarithmically with target concentration and time.

Electrical screening effects influence sensor sensitivity.

Fractal surface dimension impacts sensor response.

Abstract

Despite tremendous potential of highly sensitive electronic detection of bio-molecules by nanoscale biosensors for genomics and proteomic applications, many aspects of experimentally observed sensor response (S) are unexplained within consistent theoretical frameworks of kinetic response or electrical screening. In this paper, we combine analytic solutions of Poisson-Boltzmann and reaction-diffusion equations to show that the electrical response of nanobiosensor varies logarithmically with the concentration of target molecules, time, the salt concentration, and inversely with the fractal dimension of sensor surface. Our analysis provides a coherent theoretical interpretation of wide variety of puzzling experimental data that have so far defied intuitive explanation.