Prosper Kanyong

The reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-hydroxethyl methacrylate (HEMA) from a surface confined, dithio-tethered, chain transfer agent (CTA) enables the preparation of electrode-tethered poly (2-hydroxyethyl methacrylate) (pHEMA) brushes of well-defined thickness with convenience and exceptionally high interfacial impedimetric baseline stability. The subsequent covalent integration of antibodies generates interfaces of very high target recognition specificity, ultimately enabling fM levels of quantification of C-reactive protein (CRP) and recovery in spiked serum samples of ~98%. When combined with the intrinsic scalability of the reagentless EIS platform and the innate high levels of polymer tuneability and control, we believe this represents a valuable contribution to the diagnostic toolbox.

This review discusses recent advances in the development of biosensors for the purposes of malaria diagnostics. It underscore relevant challenges that have defined the gap between biosensor development and their successful utilization in routine clinical practice within resource-limitted settings. It proposes a way to think about developing biosensors that are suitable for biomedical diagnostics applications.

The impact of malaria on global health has continually prompted the need to develop more effective diagnostic strategies that could overcome deficiencies in accurate and early detection. In this review, we examine the various biosensor-based methods for malaria diagnostic biomarkers, namely; Plasmodium falciparum histidine-rich protein 2 (PfHRP-2), parasite lactate dehydrogenase (pLDH), aldolase, glutamate dehydrogenase (GDH), and the biocrystal hemozoin. The models that demonstrate a potential for field application have been discussed, looking at the fabrication and analytical performance characteristics, including (but not exclusively limited to): response time, sensitivity, detection limit, linear range, and storage stability, which are first summarized in a tabular form and then described in detail. The conclusion summarizes the state-of-the-art technologies applied in the field, the current challenges and the emerging prospects for malaria biosensors.

In seeking to develop and optimize reagentless electroanalytical assays, a consideration of the transducing interface features lies key to any subsequent sensitivity and selectivity. This review briefly summarizes some of the most commonly used receptive interfaces that have been employed within the development of impedimetric molecular sensors. We discuss the use of high surface area carbon, nanoparticles, and a range of bioreceptors that can subsequently be integrated. The review spans the most commonly utilized biorecognition elements, such as antibodies, antibody fragments, aptamers, and nucleic acids, and touches on some novel emerging alternatives such as nanofragments, molecularly imprinted polymers, and bacteriophages. Reference is made to the immobilization chemistries available along with a consideration of both optimal packing density and recognition probe orientation. We also discuss assay-relevant mechanistic details and applications in real sample analysis.

This paper reports the development and application of a disposable sensor for the individual and simultaneous voltammetric determination of dopamine (DA) and N-acetyl-p-aminophenol (APAP). The sensor was fabricated by drop-coating graphene nanoplatelets (GNPs)-Nafion (Naf) nanocomposite onto the working area of a screen-printed electrode (SPE). The sensor, designated as GNPs-Naf/SPE, was characterized by scanning electron microscopy (SEM), Raman spectroscopy, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Differential pulse voltammetry (DPV) was used to simultaneously analyze DA and APAP in their binary mixtures. It showed excellent selectivity and sensitivity toward both compounds with limit of detection of 0.13 µM and 0.25 µM (S/N = 3) for DA and APAP, respectively. The performance of the sensor was evaluated by analyzing the compounds in human urine samples, and the recoveries were found to be well over 97.0%.