title: Amperometric immunosensor based on gold nanoparticles/alumina sol-gel modified screen-printed electrodes for antibodies to Plasmodium falciparum histidine rich protein-2.
abstract: We report herein the amperometric immunosensor for antibodies to Plasmodium falciparum histidine rich protein-2 (PfHRP-2). Screen-printed electrodes (SPEs) were modified with alumina sol-gel (Al(2)O(3) sol-gel) derived film and gold nanoparticles i.e. AuNPs/Al(2)O(3)sol-gel/SPE. A thin film was formed by dripping Al(2)O(3) sol on SPE followed by electrochemical deposition of gold nanoparticles (AuNPs). The modified SPEs were characterized by scanning electron microscopy/energy dispersive X-ray analysis (SEM-EDAX), Raman spectra and voltammetric experiments. Antibodies in rabbit serum sample were allowed to react with the PfHRP-2 protein that was immobilized on the modified SPE to form antigen-antibody immune complex (PfHRP-2/anti-PfHRP-2). The bound antibodies were quantified by alkaline phosphatase (AP) enzyme labeled secondary antibodies (anti-rabbit immunoglobulins-AP conjugate). Enzymatic substrate, 1-naphthyl phosphate was converted to 1-naphthol by AP and an electroactive product was quantified using amperometry. The performances of the developed immunosensor and Dot-ELISA were tested against different dilutions of hyper immune serum (rabbit anti-PfHRP-2). Dot ELISA and the developed immunosensor (AuNPs/Al(2)O(3)sol-gel/SPE) results for the hyper immune serum containing anti-PfHRP-2 were distinctly positive when diluted upto 8 times (1 : 12800 dilution) and 11 times (1 : 102400 dilution), respectively. The developed immunosensor was applied for antibodies to PfHRP-2 in human clinical samples.
authors.affiliation: Defence Research & Development Establishment, Jhansi Road, Gwalior, 474002, India.
authors.forename: Mukesh K
authors.initials: MK
authors.lastname: Sharma
authors.forename: Gauri S
authors.initials: GS
authors.lastname: Agarwal
authors.forename: Vepa K
authors.initials: VK
authors.lastname: Rao
authors.forename: Sanjay
authors.initials: S
authors.lastname: Upadhyay
authors.forename: S
authors.initials: S
authors.lastname: Merwyn
authors.forename: Natarajan
authors.initials: N
authors.lastname: Gopalan
authors.forename: Ganga P
authors.initials: GP
authors.lastname: Rai
authors.forename: R
authors.initials: R
authors.lastname: Vijayaraghavan
authors.forename: Shri
authors.initials: S
authors.lastname: Prakash
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000913:Antibodies, Protozoan / Q000097:blood*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques; D004566:Electrodes; D004797:Enzyme-Linked Immunosorbent Assay; D005782:Gels; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010963:Plasmodium falciparum / Q000276:immunology*; D011506:Proteins / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*; D000099053:Histidine-Rich Glycoprotein
chemical_list: D000913:Antibodies, Protozoan; D005782:Gels; D011506:Proteins; D015800:Protozoan Proteins; D000099053:Histidine-Rich Glycoprotein; D006046:Gold; D000537:Aluminum Oxide