title: Nanostructured NiO-based reagentless biosensor for total cholesterol and low density lipoprotein detection.
abstract: Nanostructured nickel oxide (NiO) thin film has been explored as a matrix to develop a reagentless biosensor for free and total cholesterol as well as low density lipoprotein (LDL) detection. The redox property of the matrix has been exploited to enhance the electron transfer between the enzyme and the electrode as well as to eliminate the toxic mediator in solution. X-ray diffraction, scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy were carried out to characterize the NiO thin film. Biosensing response studies were accomplished using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The developed biosensors exhibited a high sensitivity of 27 and 63 μA/mM/cm2over a linear range of 0.12-10.23 and 1-12 mM, respectively, for free and total cholesterol. Reagentless estimation of LDL was also achieved over the wide range 0.018-0.5 μM with a sensitivity of 0.12 mA/μM/cm2. The results are extremely promising for the realization of an integrated biosensor for complete detection of cholesterol in the serum samples. Graphical Abstract Reagentless sensing mechanism of (a) free cholesterol and (b) total cholesterol using nanostructured NiO matrix.
authors.affiliation: Department of Physics and Astrophysics, University of Delhi, Delhi, 110007, India.
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Kaur
authors.affiliation: Physics Department, Miranda House, University of Delhi, Delhi, 110007, India.
authors.forename: Monika
authors.initials: M
authors.lastname: Tomar
authors.affiliation: Department of Physics and Astrophysics, University of Delhi, Delhi, 110007, India. drguptavinay@gmail.com.
authors.forename: Vinay
authors.initials: V
authors.lastname: Gupta
mesh_terms: D015374:Biosensing Techniques; D002784:Cholesterol / Q000032:analysis*; D008077:Lipoproteins, LDL / Q000032:analysis*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D009532:Nickel / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D008077:Lipoproteins, LDL; D009532:Nickel; D002784:Cholesterol; C028007:nickel monoxide
keywords: Cholesterol; Low density lipoprotein; Nickel oxide; Reagentless biosensor