A miniature and reusable radiofrequency biosensor combining microfluidic and integrated passive technology for glucose detection

Abstract

This work demonstrates a microfluidic radiofrequency (RF) biosensor system consisting of a resonator-based chip that provides a high-intensity surface electromagnetic field with measured parameters and a microfluidic chamber that provides a cavity for loading glucose solution, which together enable non-contact, fast, and real-time glucose measurements. The sensing relies on RF parameters affected by the changes in the permittivity of different glucose concentration solutions. Modeling and analysis of RF chip with different microfluidic module configurations are presented to construct an optimum high-sensitivity system with a compact size of 2 × 2 × 0.5 cm3. The experimental results showed that the constructed system exhibited high sensitivity (0.163 dB*ml/mg) and a wide detection range (0.32–9 mg/ml). The system possesses real-time detection capability and anti-interference ability. Moreover, other RF-parameter responses (S12, phase, Smith chart, real, and imaginary) curves to concentration were explored with exhibiting regular variations. Especially, multiple-parameters combination enabled system distinguishability on single-solute solutions. Taking advantage of RF detection combined with microfluidic for glucose detection, this study provides perspective insights into optimum RF sensor construction and extends its potential applications.