title: Reduced Graphene Oxide Modified the Interdigitated Chain Electrode for an Insulin Sensor.
abstract: Insulin is a key regulator in glucose homeostasis and its deficiency or alternations in the human body causes various types of diabetic disorders. In this paper, we present the development of a reduced graphene oxide (rGO) modified interdigitated chain electrode (ICE) for direct capacitive detection of insulin. The impedance properties of rGO-ICE were characterized by equivalent circuit modeling. After an electrochemical deposition of rGO on ICE, the electrode was modified with self-assembled monolayers and insulin antibodies in order to achieve insulin binding reactions. The impedance spectra and capacitances were measured with respect to the concentrations of insulin and the capacitance change (ΔC) was analyzed to quantify insulin concentration. The antibody immobilized electrode showed an increment of ΔC according to the insulin concentration in human serum ranging from 1 ng/mL to 10 µg/mL. The proposed sensor is feasible for label-free and real-time measuring of the biomarker and for point-of-care diagnosis.
authors.affiliation: Department of Biomedical Engineering, Gachon University, 191 Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Korea. yagati@gachon.ac.kr.|Gachon Advanced Institute for Health Science &amp; Technology, Gachon University, 155 Get-Pearl-ro, Yeonsu-gu, Incheon 21999, Korea. yagati@gachon.ac.kr.
authors.forename: Ajay Kumar
authors.initials: AK
authors.lastname: Yagati
authors.affiliation: Gachon Advanced Institute for Health Science &amp; Technology, Gachon University, 155 Get-Pearl-ro, Yeonsu-gu, Incheon 21999, Korea. jspark88@gc.gachon.ac.kr.
authors.forename: Jinsoo
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Biomedical Engineering, Gachon University, 191 Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Korea. sbcho@gachon.ac.kr.|Gachon Advanced Institute for Health Science &amp; Technology, Gachon University, 155 Get-Pearl-ro, Yeonsu-gu, Incheon 21999, Korea. sbcho@gachon.ac.kr.
authors.forename: Sungbo
authors.initials: S
authors.lastname: Cho
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D058266:Dielectric Spectroscopy; D025802:Electric Capacitance; D004566:Electrodes; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*
chemical_list: D007328:Insulin; D010087:Oxides; D006108:Graphite
keywords: capacitive biosensor; graphene oxide; impedance spectroscopy; insulin; interdigitated electrode