Spectrally filtered photodiode pairs for on-chip ratiometric aptasensing of cytokine dynamics

• Published in: Sensors and actuators. B, Chemical Chemical, 2021-10, Vol.345, p.130330, Article 130330
• Main Authors: Xiong, Zheshun, Ren, Kewei, Donnelly, Matthew, You, Mingxu, Xu, Guangyu
• Format: Article
• Language: English
• Subjects: Biomarkers; Cytokine dynamics; Cytokines; Fluorescence; Immune response monitoring; Immune system; Interferon; On-chip fluorescence sensing; Photodiodes; Ratiometric aptasensing; Real time operation; Sensors; Spectrally filtered photodiode pairs
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2021.130330

•On-chip ratiometric aptasensing with spectrally filtered photodiode pairs.•Cytokine biosensors with low detection limit and robust reusability.•Rapid detection of interferon-gamma dynamics with low drift and low variation.•Advancing point-of-care testing systems for immune response monitoring. Miniaturized, cost-effective cytokine sensing devices are essential for health monitoring and critical care of patients with acute immune responses. Here we report an on-chip ratiometric aptasensing device to monitor the dynamics of an essential immune response biomarker, interferon-gamma. Our device is formed by pairs of spectrally filtered silicon photodiodes that are surface functionalized with aptamer probes. These photodiode pairs are able to rapidly detect two-color fluorescence changes transduced from aptamer-cytokine binding events within c.a. 6 min at picomolar levels, which are sufficient to capture the cytokine transients in point-of-care settings. Furthermore, our device can be reset to baseline by simple washing steps, yielding consistent readout in consecutive runs. Combined with their chip-scale construct and real-time operation, our cytokine sensors may have possible use in point-of-care and therapeutic screening applications.