Sensitive, specific, rapid, inexpensive and easy-to-use nucleic acid tests for use at the point-of-need are critical for the emerging field of personalised medicine for which companion diagnostics are essential, as well as for application in low resource settings. Here we report on the development of a point-of-care nucleic acid lateral flow test for the direct detection of isothermally amplified DNA. The recombinase polymerase amplification method is modified slightly to use tailed primers, resulting in an amplicon with a duplex flanked by two single stranded DNA tails. This tailed amplicon facilitates detection via hybridisation to a surface immobilised oligonucleotide capture probe and a gold nanoparticle labelled reporter probe. A detection limit of 1 × 10−11 M (190 amol), equivalent to 8.67 × 105 copies of DNA was achieved, with the entire assay, both amplification and detection, being completed in less than 15 minutes at a constant temperature of 37 °C. The use of the tailed primers obviates the need for hapten labelling and consequent use of capture and reporter antibodies, whilst also avoiding the need for any post-amplification processing for the generation of single stranded DNA, thus presenting an assay that can facilely find application at the point of need.

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The inside cover picture shows the catalytic degradation of a stem‐loop motif of the structured hepatitis C IRES RNA in an HCV‐infected liver cell. Catalytic metallodrugs promote irreversible degradation of the RNA and demonstrate significant antiviral activity in a cellular HCV replicon assay. MALDI‐TOF mass spectrometry combined with computational analysis provides insights into the site‐specific cleavage mechanism. For more details, see the Full Paper by James A. Cowan et al. on

An electrochemical sensor for the sensitive and selective detection of cysteine is proposed based on a gold nanoparticle (AuNP)–iron(iii) phthalocyanine (FePc) modified graphite paste electrode.

A cellulose nanocrystal (CNC) material was converted into its dialdehyde before being decorated with gold nanoparticles (AuNPs) through an aminothiophenol linker.

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Bismuth film modified and chemically activated carbon micro‐thread electrodes were investigated for the simultaneous determination of Cd(II) and Pb(II) using square wave anodic stripping voltammetry. The carbon thread electrode was characterised using both surface and electrochemical techniques. Electrochemical impedance spectroscopy (EIS) studies demonstrated that the H2SO4/IPA‐treated carbon thread electrode showed a much improved resistance response (Rct=23 Ω) compared to the IPA‐untreated carbon thread (Rct=8317 Ω). Furthermore, parameters such as the effect of deposition potential, deposition time and Bi(III) concentration were explored using square wave voltammetry. Detection limits (S/N=3) for Cd(II) and Pb(II) were found to be 1.08 µg L−1 and 0.87 µg L−1, respectively and response was found to be linear over the range 5–110 µg L−1. The proposed Bi/IPA‐treated carbon thread electrode exhibited a high selectivity towards Cd(II) and Pb(II) even in the presence of a range of heavy metals and is capable of repetitive and reproducible measurements, being attributed to the high surface area, geometry and electrode treatment characteristics. The proposed metal ion sensor was employed to determine cadmium and lead in river water samples and % RSD was found to be 5.46 % and 5.93 % for Cd(II) and Pb(II) respectively (n=3). Such facile sensing components favour the development of cost effective portable devices for environmental sample analysis and electrochemical applications.

A hydrogen peroxide (H2O2) sensor was developed based on core–shell gold@titanium dioxide nanoparticles and multi-walled carbon nanotubes modified by a glassy carbon electrode (Au@TiO2/MWCNTs/GCE). Core–shell Au@TiO2 material was prepared and characterized using a scanning electron microscope and energy dispersive X-ray analysis (SEM/EDX), transmission electron microscopy (TEM), atomic force microscope (AFM), Raman spectroscopy, X-ray diffraction (XRD) and Zeta-potential. The proposed sensor (Au@TiO2/MWCNTs/GCE) was investigated electrochemically using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The analytical performance of the sensor was evaluated towards H2O2 using differential pulse voltammetry (DPV). The proposed sensor exhibited excellent stability and sensitivity with a linear concentration range from 5 to 200 µM (R2 = 0.9973) and 200 to 6000 µM (R2 = 0.9994), and a limit of detection (LOD) of 1.4 µM achieved under physiological pH conditions. The practicality of the proposed sensor was further tested by measuring H2O2 in human serum and saliva samples. The observed response and recovery results demonstrate its potential for real-world H2O2 monitoring. Additionally, the proposed sensor and detection strategy can offer potential prospects in electrochemical sensors development, indicative oxidative stress monitoring, clinical diagnostics, general cancer biomarker measurements, paper bleaching, etc.