title: Studies on an on/off-switchable immunosensor for troponin T.
abstract: Regeneration is a key goal in the design of immunosensors. In this study, we report the temperature-regulated interaction of N-isopropylacrylamide (PNIPAAm) functionalised cardiac troponin T (cTnT) with anti-cTnT. Covalently bonded PNIPAAm on an anti-cTnT bioelectrode showed on/off-switchability, regeneration capacity and temperature triggered sensitivity for cTnT. Above the lower critical solution temperature (LCST), PNIPAAm provides a liphophilic microenvironment with specific volume reduction at the bioelectrode surface, making available binding space for cTnT, and facilitating analyte recognition. Computational studies provide details about the structural changes occurring at the electrode above and below the LCST. Furthermore, free energies associated with the binding of cTnT with PNIPAAm at 25 (ΔGcoil=-6.0 Kcal/mole) and 37 °C (ΔGglobular=-41.0 kcal/mole) were calculated to elucidate the interaction and stability of the antigen-antibody complex. The responsiveness of such assemblies opens the way for miniaturised, smart immuno-technologies with 'built-in' programmable interactions of antigen-antibody upon receiving stimuli.
authors.affiliation: Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 581 83, Sweden; Department of Applied Chemistry and Chemical Engineering, University of Dhaka, Dhaka 1000, Bangladesh.
authors.forename: Md
authors.initials: M
authors.lastname: Ashaduzzaman
authors.affiliation: Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 581 83, Sweden.
authors.forename: Aswathi
authors.initials: A
authors.lastname: Anto Antony
authors.affiliation: Virtual Laboratory for Molecular Probes, Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, Stockholm 106 91, Sweden.
authors.forename: N
authors.initials: N
authors.lastname: Arul Murugan
authors.affiliation: Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 581 83, Sweden.
authors.forename: Swapneel R
authors.initials: SR
authors.lastname: Deshpande
authors.affiliation: Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 581 83, Sweden.
authors.forename: Anthony P F
authors.initials: APF
authors.lastname: Turner
authors.affiliation: Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 581 83, Sweden; Tekidag AB, UCS, Teknikringen 4A, Mjärdevi Science Park, Linköping 583 30, Sweden. Electronic address: ashutosh.tiwari@liu.se.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Tiwari
mesh_terms: D000180:Acrylic Resins; D055910:Antibodies, Immobilized / Q000737:chemistry; D000936:Antigen-Antibody Complex / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques; D017743:Equipment Reuse; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D011487:Protein Conformation; D013696:Temperature; D013816:Thermodynamics; D044366:Transition Temperature; D020107:Troponin T / Q000032:analysis* / Q000276:immunology
chemical_list: D000180:Acrylic Resins; D055910:Antibodies, Immobilized; D000936:Antigen-Antibody Complex; D020107:Troponin T; C052970:poly-N-isopropylacrylamide
keywords: On/off-switching; Programmable bioelectronics; Smart immunosensors; Troponin T