title: Nano-yeast-scFv probes on screen-printed gold electrodes for detection of Entamoeba histolytica antigens in a biological matrix.
abstract: The time and costs associated with monoclonal antibody production limit the potential for portable diagnostic devices to penetrate the market. Replacing the antibody with a low-cost alternate affinity reagent would reduce the costs of diagnostic development and use, and lead to new portable diagnostic devices towards many diseases. Herein, we present low-cost affinity reagents, nano-yeast-scFv, on commercially available, inexpensive, and portable screen-printed electrodes for the label-free electrochemical detection of Entamoeba histolytica cyst antigens. The biosensor was able to detect antigen at concentrations down to 10 pg mL(-1) in buffer with an inter-assay reproducibility of (% RSD, n=3) 4.1%. The applicability of two differently engineered nano-yeast-scFv to each specifically detect their cognant E. histolytica cyst antigens was demonstrated in a biological matrix derived from human stool. Because of the simple, inexpensive, and sensitive nature of this methodology, it may offer a low-cost alternative to immunosensors based on antibody-target recognition.
authors.affiliation: Centre for Biomarker Research and Development, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Yadveer S
authors.initials: YS
authors.lastname: Grewal
authors.affiliation: Centre for Biomarker Research and Development, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane QLD 4072, Australia. Electronic address: m.shiddiky@uq.edu.au.
authors.forename: Muhammad J A
authors.initials: MJ
authors.lastname: Shiddiky
authors.affiliation: School of Public Health University of Washington, Seattle, WA, USA.
authors.forename: Lauren J
authors.initials: LJ
authors.lastname: Spadafora
authors.affiliation: School of Public Health University of Washington, Seattle, WA, USA.
authors.forename: Gerard A
authors.initials: GA
authors.lastname: Cangelosi
authors.affiliation: Centre for Biomarker Research and Development, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane QLD 4072, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane QLD 4072, Australia. Electronic address: m.trau@uq.edu.au.
authors.forename: Matt
authors.initials: M
authors.lastname: Trau
mesh_terms: D000953:Antigens, Protozoan / Q000032:analysis* / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004748:Entamoeba histolytica / Q000276:immunology* / Q000302:isolation & purification; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005243:Feces / Q000469:parasitology*; D005656:Fungal Proteins / Q000276:immunology; D006046:Gold; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry; D015336:Molecular Probe Techniques; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D057127:Single-Chain Antibodies / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan; D005656:Fungal Proteins; D057127:Single-Chain Antibodies; D006046:Gold
keywords: Affinity reagent; Electrochemical immunosensor; Entamoeba histolytica; Label-free detection; Nano-yeast–scFv; Screen-printed electrode