title: Ultrasensitive cardiac troponin I antibody based nanohybrid sensor for rapid detection of human heart attack.
abstract: An ultrasensitive cardiac troponin I antibody conjugated with graphene quantum dots (GQD) and polyamidoamine (PAMAM) nanohybrid modified gold electrode based sensor was developed for the rapid detection of heart attack (myocardial infarction) in human. Screen printed gold (Au) electrode was decorated with 4-aminothiophenol for amine functionalization of the Au surface. These amino groups were further coupled with carboxyl functionalities of GQD with EDC-NHS reaction. In order to enhance the sensitivity of the sensor, PAMAM dendrimer was successively embedded on GQD through carbodiimide coupling to provide ultra-high surface area for antibody immobilization. The activated cardiac troponin I (cTnI) monoclonal antibody was immobilized on PAMAM to form nanoprobe for sensing specific heart attack marker cTnI. Various concentrations of cardiac marker, cTnI were electrochemically measured using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in human blood serum. The modifications on sensor surface were characterized by FTIR and AFM techniques. The sensor is highly specific to cTnI and showed negligible response to non-specific antigens. The sensitivity of the sensor was 109.23μAcm-2μg-1and lower limit of detection of cTnI was found 20fgmL-1.
authors.affiliation: CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India; CSIR-Central Scientific Instruments Organisation, Sector 30-C, Chandigarh, 160030, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
authors.forename: Deepika
authors.initials: D
authors.lastname: Bhatnagar
authors.affiliation: CSIR-Central Scientific Instruments Organisation, Sector 30-C, Chandigarh, 160030, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India. Electronic address: inderpreety@yahoo.co.in.
authors.forename: Inderpreet
authors.initials: I
authors.lastname: Kaur
authors.affiliation: CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India. Electronic address: ashokigib@rediffmail.com.
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D050091:Dendrimers / Q000737:chemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D057230:Limit of Detection; D009203:Myocardial Infarction / Q000175:diagnosis*; D045663:Quantum Dots / Q000737:chemistry; D013997:Time Factors; D019210:Troponin I / Q000276:immunology*
chemical_list: D055910:Antibodies, Immobilized; D000911:Antibodies, Monoclonal; D050091:Dendrimers; C104700:PAMAM Starburst; D019210:Troponin I; D006046:Gold; D006108:Graphite
keywords: Cardiac troponin I; Graphene quantum dots; Heart attack; Myocardial infarction; PAMAM dendrimer