In-Situ Integration of 3D C-MEMS Microelectrodes with Bipolar Exfoliated Graphene for Label-Free Electrochemical Cancer Biomarkers Aptasensor.

Shahrzad Forouzanfar,Chunlei Wang,Nezih Pala

doi:10.3390/mi13010104

Shahrzad Forouzanfar, Chunlei Wang + Show 1 more

Open Access

https://doi.org/10.3390/mi13010104

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Abstract

The electrochemical label-free aptamer-based biosensors (also known as aptasensors) are highly suitable for point-of-care applications. The well-established C-MEMS (carbon microelectromechanical systems) platforms have distinguishing features which are highly suitable for biosensing applications such as low background noise, high capacitance, high stability when exposed to different physical/chemical treatments, biocompatibility, and good electrical conductivity. This study investigates the integration of bipolar exfoliated (BPE) reduced graphene oxide (rGO) with 3D C-MEMS microelectrodes for developing PDGF-BB (platelet-derived growth factor-BB) label-free aptasensors. A simple setup has been used for exfoliation, reduction, and deposition of rGO on the 3D C-MEMS microelectrodes based on the principle of bipolar electrochemistry of graphite in deionized water. The electrochemical bipolar exfoliation of rGO resolves the drawbacks of commonly applied methods for synthesis and deposition of rGO, such as requiring complicated and costly processes, excessive use of harsh chemicals, and complex subsequent deposition procedures. The PDGF-BB affinity aptamers were covalently immobilized by binding amino-tag terminated aptamers and rGO surfaces. The turn-off sensing strategy was implemented by measuring the areal capacitance from CV plots. The aptasensor showed a wide linear range of 1 pM–10 nM, high sensitivity of 3.09 mF cm−2 Logc−1 (unit of c, pM), and a low detection limit of 0.75 pM. This study demonstrated the successful and novel in-situ deposition of BPE-rGO on 3D C-MEMS microelectrodes. Considering the BPE technique’s simplicity and efficiency, along with the high potential of C-MEMS technology, this novel procedure is highly promising for developing high-performance graphene-based viable lab-on-chip and point-of-care cancer diagnosis technologies.

Highlights

Introduction iationsThe recent COVID-19 pandemic showed the importance of fast and on-site detection of pathogens in preventing and helping infected patients
The results revealed that the integration of bipolar exfoliated (BPE)-reduced graphene oxide (rGO) with 3D Carbon-based microelectrochemical devices (C-MEMS)
3D C-MEMS microelectrodes consisted of a thin current lector electrode decorated with micropillars with a radius of 25 μ m and a height of apcollector electrode decorated with micropillars with a radius of 25 μm and a height of proximately 100 μ m

Summary

Introduction

The recent COVID-19 pandemic showed the importance of fast and on-site detection of pathogens in preventing and helping infected patients. The point-of-care (POC) biosensor can be used for fast and reliable detection of different pathogens and biomarkers on-site of patients. The POC biosensors can be a powerful tool for early diagnosis and monitoring cancer disease patients. The largest benefit of POC sensing compared to conventional laboratory-based testing is that it can be done rapidly and be performed by clinical personnel who are not trained in clinical laboratory sciences. POC test results can provide a physician—and other clinical personnel—with answers that can quickly help determine a course of action or treatment for a patient [1,2]. The high fatality of most cancer diseases can be associated with the late diagnosis of these diseases, Licensee MDPI, Basel, Switzerland

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