Interferon gamma (IFN-γ)-sensitive TB aptasensor based on novel chitosan-indium nano-kesterite (χtCITS)-labeled DNA aptamer hairpin technology

Onyinyechi Uhuo; Tesfaye Waryo; Marlon Oranzie; Nelia Sanga; Zandile Leve; Jaymi January; Ziyanda Tshobeni; Keagan Pokpas; Samantha Douman; Emmanuel Iwuoha

doi:10.1016/j.bioelechem.2024.108693

Interferon gamma (IFN-γ)-sensitive TB aptasensor based on novel chitosan-indium nano-kesterite (χtCITS)-labeled DNA aptamer hairpin technology

Bioelectrochemistry. 2024 Mar 18:158:108693. doi: 10.1016/j.bioelechem.2024.108693. Online ahead of print.

Authors

Affiliations

¹ SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, University of the Western Cape, Bellville 7535, Cape Town, South Africa. Electronic address: 3824535@myuwc.ac.za.
² SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, University of the Western Cape, Bellville 7535, Cape Town, South Africa.
³ SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, University of the Western Cape, Bellville 7535, Cape Town, South Africa; Department of Chemistry, PD Hahn Building, 28 Chemistry Road, Upper Campus, University of Cape Town, Private Bag X3, Rondebosch 7701, Cape Town, South Africa.
⁴ SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, University of the Western Cape, Bellville 7535, Cape Town, South Africa. Electronic address: eiwuoha@uwc.ac.za.

PMID: 38554559
DOI: 10.1016/j.bioelechem.2024.108693

Abstract

There has been increasing interest in the use of biosensors for diagnosis of infectious diseases such as tuberculosis (TB) due to their simplicity, affordability, and potential for point-of-care application. The incorporation of aptamer molecules and nanomaterials in biosensor fabrication explores the advantages of high-binding affinity and low immunogenicity of aptamers as well as the high surface-to-volume ratio of nanomaterials, for increased aptasensor performance. In this work, we employed a novel microwave-synthesized copper indium tin sulfide (CITS) substituted-kesterite nanomaterial, together with a natural biopolymer (chitosan), for signal amplification and increased loading of aptamer molecules. Study of the optical properties of CITS nanomaterials showed strong absorption in the UV region characteristic of kesterite semiconductor nanomaterials. X-ray diffraction analysis confirmed the presence of the kesterite phase with average crystallite size of 6.188 nm. Fabrication of interferon-gamma (IFN-γ) TB aptasensor with a chitosan-CITS nanocomposite (χtCITS) increased the aptasensor's electrochemical properties by 77.5 % and improved aptamer loading by 73.7 %. The aptasensor showed excellent sensitivity to IFN-γ concentrations with limit of detection of 6885 fg/mL (405 fM) and linear range of 850-17000 fg/mL (50 - 1000 fM). The aptasensor also exhibited excellent storage and electrochemical stability, with good selectivity towards IFN-γ and possible real sample application.

Keywords: Copper indium tin sulfide; Hairpin aptamer; Methylene blue; Nanomaterial; Substituted-kesterite; Tuberculosis Biosensor.