An electrochemical genosensor for Leishmania major detection based on dual effect of immobilization and electrocatalysis of cobalt-zinc ferrite quantum dots

Abstract

Identification of Leishmania parasites is important in diagnosis and clinical studies of leishmaniasis. Although epidemiological and clinical methods are available, they are not sufficient for identification of causative agents of leishmaniasis. In the present study, quantum dots of magnetic cobalt-zinc ferrite (Co0.5Zn0.5Fe2O4) were synthesized and characterized by physicochemical methods. The quantum dots were then employed as an electrode modifier to immobilize a 24-mer specific single stranded DNA probe, and fabrication of a label-free, PCR-free and signal-on electrochemical genosensor for the detection of Leishmania major. Hybridization of the complementary single stranded DNA sequence with the probe under the selected conditions was explored using methylene blue as a redox marker, utilizing the electrocatalytic effect of the quantum dots on the methylene blue electroreduction process. The genosensor could detect a synthetic single stranded DNA target in a range of 1.0×10(-11) to 1.0×10(-18)molL(-1) with a limit of detection of 2.0×10(-19)molL(-1), and genomic DNA in a range of 7.31×10(-14) to 7.31×10(-6)ngμL(-1) with a limit of detection of 1.80×10(-14)ngμL(-1) with a high selectivity and sensitivity.

Electrochemical Biosensing for the Diagnosis of Viral Infections and Tropical Diseases

“…QDs of magnetic cobalt‐zinc ferrite (Co 0.5 Zn 0.5 Fe 2 O 4 ) were synthesized and employed as an electrode modifier to immobilize a 24‐mer specific single‐stranded (ss)‐DNA probe for the fabrication of a label‐free, PCR‐free and signal‐on electrochemical DNA sensor for the detection of Leishmania major . Hybridization of the complementary ss‐DNA sequence with the probe was explored using methylene blue (MB) as a redox marker, utilizing the electrocatalytic effect of the QDs on the MB electroreduction process . The applicability of the DNA sensor for diagnosis of cutaneous leishmania in patients was tested by analyzing biopsy specimens of 6 human samples (5 positive in L major and 1 positive in L tropica ).…”

Examination of structral morphological and magnetic behaviour of ZnFe2O4 nanoparticle synthesised by co-pricipitation method

“…Depending upon the physical properties differ intensely from their bulk complements rising behind their small size. In a particular manner, magnetic nanoparticles (MNPs) from their smaller size, non-toxicity, inject ability, biocompatibility and high leveling in biomedical applications [12,13]. Transition metal oxides and metal sulfides are extensively studied due to their verity of potential applications [14][15][16][17].…”

Applications of Nanoflowers in Biomedicine

“…Up to now, nanostructured materials of different shapes have been synthesized, e.g. nanoparticle [21][22][23], nanoshell [24], nanoflake [25], core@shell [26,27], nanotube [28], nanosheet [29,30], nanofibril [31], nanorod [32], nanoshale [33], dot [34], nanospear [35] etc. "Nanoflowers" is a term used recently by researchers for a particular group of nanostructures that are similar to flowers in microscopic view [36,37].…”