Temporal response of biochemical and biological sensors with bimodal surface adsorption from a finite sample

Ivana Jokić; Olga Jakšić; Miloš Frantlović; Zoran Jakšić; Koushik Guha; Karumuri Srinivasa Rao

doi:10.1007/s00542-020-05051-w

Temporal response of biochemical and biological sensors with bimodal surface adsorption from a finite sample

Microsyst Technol. 2021;27(8):2981-2987. doi: 10.1007/s00542-020-05051-w. Epub 2020 Oct 6.

Authors

Ivana Jokić¹, Olga Jakšić¹, Miloš Frantlović¹, Zoran Jakšić¹, Koushik Guha², Karumuri Srinivasa Rao³

Affiliations

¹ Center of Microelectronic Technologies, Institute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, 11000 Belgrade, Serbia.
² National MEMS Design Centre, Department of Electronics and Communication Engineering, National Institute of Technology, Silchar, Assam, Silchar, 788010 India.
³ Head of Microelectronics Research Group, Department of Electronics and Communication Engineering, KL University, Green Fields, Vaddeswaram, Gunter, Andhra Pradesh 522502 India.

Abstract

The importance of adsorption-based biochemical/biological sensors in biochemistry and biophysics is paramount. Their temporal response gives information about the presence of a biochemical/biological analyte, its concentration and its interactions with the adsorption sites (which may be an integral part of the surface itself or immobilized functionalizing molecules). Mathematical models of the temporal response taking into account as many relevant effects as possible are essential for obtaining reliable information. We present a novel model taking into account the bimodal affinity of a sensing surface (adsorption occurs on two distinct site types), and the adsorption-caused depletion of the analyte from the sample. We perform qualitative and quantitative analysis of the analyte depletion influence on the bimodal adsorption, and of the influence of the sensing surface inhomogeneity on the sensor temporal response, for different analyte concentrations and different fractions of two types of adsorption sites. Since the presented mathematical model deals with the realistic cases of the sensing surface non-uniformity and the finite amount of analyte present in the sensor reaction chamber, it enables improved accuracy in interpreting the measurement data. Our results are general, i.e. valid for any adsorption sensor (microcantilevers, plasmonics) and for arbitrary sensor dimensions.