A Novel Carbon Nanofibers Grown on Glass Microballoons Immunosensor: A Tool for Early Diagnosis of Malaria

Abstract

This paper presents a novel method for direct detection of Plasmodium falciparum histidine rich protein-2 (PfHRP-2) antigen using carbon nanofiber (CNF) forests grown on glass microballoons (NMBs). Secondary antibodies specific to PfHRP-2 densely attached to the CNFs exhibit extraordinary ability for the detection of minute concentrations of Plasmodium species. A sandwich immunoassay protocol was employed, where a glass substrate was used to immobilize primary antibodies at designated capture zones. High signal amplification was obtained in both colorimetric and electrical measurements due to the CNFs through specific binding. As a result, it was possible to detect PfHRP-2 levels as low as 0.025 ng/mL concentration in phosphate buffered saline (PBS) using a visual signal within only 1 min of test duration. Lower limits of 0.01 ng/mL was obtained by measuring the electrical resistivity of the capture zone. This method is also highly selective and specific in identifying PfHRP-2 and other Plasmodium species from the same solution. In addition, the stability of the labeling mechanism eliminates the false signals generated by the use of dyes in current malaria rapid diagnostic test kits (MRDTs). Thus, the rapid, sensitive and high signal amplification capabilities of NMBs is a promising tool for early diagnosis of malaria and other infectious diseases.

Development of Electrochemical Nanosensor for the Detection of Malaria Parasite in Clinical Samples

“…The LoDs recorded in this work are higher than 2.5 x 10 −5 μg/mL and 4.0 x 10 −5 μg/mL reported for Plasmodium falciparum histidine-rich protein 2 (PfHRP 2) detection on screen printed gold electrode (Gikunoo et al, 2014; Aver et al, 2017). Although the LoD is higher for the present study, the use of chemical biomarkers such as β-hematin should be encouraged because they are stable, affordable (cheaper), and easily available than PfHRP 2.…”

Development of Electrochemical Nanosensor for the Detection of Malaria Parasite in Clinical Samples

“…The LoDs recorded in this work are higher than 2.5 x 10 −5 µg/mL and 4.0 x 10 −5 µg/mL reported for Plasmodium falciparum histidine-rich protein 2 (PfHRP 2) detection on screen printed gold electrode (Gikunoo et al, 2014;Aver et al, 2017). Although the LoD is higher for the present study, the use of chemical biomarkers such as β-hematin should be encouraged because they are stable, affordable (cheaper), and easily available than PfHRP 2.…”

Current Trends of Nanobiosensors for Point-of-Care Diagnostics

“…A variety of biomarkers for malaria exist. Some of these include hemozoin which is a paramagnetic nanoparticle byproduct of the malaria parasite, also known as malaria pigment or malaria biomarker [90] and whose presence in the blood is indicative of malarial infection, plasmodium falciparum histidine-rich protein 2 (PfHRP 2) [91, 92], and topoisomerase I expressed by the malaria causing Plasmodium parasite [88]. The use of hemozoin is highly recommended as a biomarker in the development of malarial diagnostic devices because it is more stable, cheaper, and easily available compared to PfHRP 2 [90].…”