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Direct label-free electrical immunodetection of transplant rejection protein biomarker in physiological buffer using
Insights
This study presents a novel, label-free biosensor for detecting Monokine induced by interferon gamma (MIG/CXCL9), a key biomarker for transplant rejection. The GaN-based HEMT biosensor enables early monitoring of immune responses.
Area of Science:
- Biomedical Engineering
- Immunology
- Materials Science
Background:
- Monokine induced by interferon gamma (MIG/CXCL9) is a crucial immune biomarker for monitoring transplant and allograft rejection.
- Early detection of MIG/CXCL9 levels is vital for timely intervention in transplant recipients.
Purpose of the Study:
- To develop and demonstrate a direct, label-free electrical detection method for MIG/CXCL9.
- To utilize a Gallium Nitride (GaN)-based High Electron Mobility Transistor (HEMT) biosensor for this detection.
Main Methods:
- A GaN-based HEMT device was biologically modified with anti-MIG IgG antibodies.
- High-affinity monoclonal antibodies were immobilized on self-assembled monolayers (SAMs) on the HEMT's gold sensing gate.
- A floating gate configuration was employed to eliminate external gate voltage influences.
Main Results:
- The biosensor demonstrated label-free detection of recombinant human MIG.
- Detection was achieved in a physiologically relevant buffer environment.
- The sensor successfully detected MIG within a concentration range of 5 ng/mL to 500 ng/mL.
Conclusions:
- The developed GaN-HEMT biosensor offers a promising platform for sensitive and direct electrical detection of MIG/CXCL9.
- This technology has the potential for early, non-invasive monitoring of transplant rejection.
- Further development could lead to improved diagnostic tools in transplantation medicine.
Abstract:
Monokine induced by interferon gamma (MIG/CXCL9) is used as an immune biomarker for early monitoring of transplant or allograft rejection. This paper demonstrates a direct electrical, label-free detection method of recombinant human MIG with anti-MIG IgG molecules in physiologically relevant buffer environment. The sensor platform used is a biologically modified GaN-based high electron mobility transistor (HEMT) device. Biomolecular recognition capability was provided by using high affinity anti-MIG monoclonal antibody to form molecular affinity interface receptors on short N-hydroxysuccinimide-ester functionalized disulphide (DSP) self-assembled monolayers (SAMs) on the gold sensing gate of the HEMT device. A floating gate configuration has been adopted to eliminate the influences of external gate voltage. Preliminary test results with the proposed chemically treated GaN HEMT biosensor show that MIG can be detected for a wide range of concentration varying from 5 ng/mL to 500 ng/mL.
