A Novel Mass-Producible Capacitive Sensor with Fully Symmetric 3D Structure and Microfluidics for Cells Detection.

Zhaorui Zuo,Vincent Ho,Dahong Qian,Hongju Mao,Kun Wang,Libin Gao

doi:10.3390/s19020325

Abstract

Affinity biosensors of interdigitated electrodes have been widely used in cell detection. This research presents a mass-producible and disposable three-dimensional (3D) structure capacitive sensor based on the integrated circuit package lead frames for cell concentration detection. The fully symmetric 3D interdigital electrode structure makes the sensor more homogeneous and sensitive. (3-Aminopropyl) triethoxysilane (APTES) and glutaraldehyde are immobilized onto gold-plated electrodes. By overlaying the microfluidic channels on top, the volume of the solution is kept constant to obtain repeatable measured capacitance values. Moreover, using the upgraded reading and writing functions and circular measurement of the E4980A Data Transfer Program, an automatic multigroup test system is developed. It is shown that the cell concentration and capacitance are inversely correlated, and the cell concentration range of 103–106 CFU∙mL−1 is achieved. In addition, the rate of capacitance change matches that of state-of-the-art biosensors reported. A program is developed to find the optimal voltage and frequency for linear fitting between the capacitance change and cell concentration. Future work will employ machine learning-based data analysis to drug resistance sensitivity test of cell lines and cell survival status.

Highlights

Affinity biosensors are based on the interaction between immobilized biological components on the transducer surface and target molecules [1]
mouse embryonic fibroblast (MEF) cells were isolated from pregnant females at embryonic day 13 (E13) and were cultured in Dulbecco’s modified Eagle’s medium supplemented with 10% fetal bovine serum, 1× nonessential amino acids, penicillin, and streptomycin
Biocell only needs a few discrete components and is easy to use for biomolecule detection applications. It is mass-producible in a WQFN-16L 3 × 3 mm package, which is suitable for embedding in point-of-care testing device

Summary

Introduction

Affinity biosensors are based on the interaction between immobilized biological components on the transducer surface and target molecules [1]. Biological elements used in affinity biosensors are typically antibodies, DNA, and receptor proteins [1], to name a few. Some new “artificial antibodies” biological sensors have been proposed, for instance, molecularly imprinted polymers (MIPs) [6] and nanoMIPs [7] have shown good results. These techniques can be promising in various applications where sensitive, selective, and label-free

Methods

Results

Conclusion