Antibiotic resistance has been cited by the World Health Organisation (WHO) as one of the greatest threats to public health. Mitigating the spread of antibiotic resistance requires a multipronged approach with possible interventions including faster diagnostic testing and enhanced antibiotic stewardship. This study employs a low-cost diagnostic sensor test to rapidly pinpoint the correct antibiotic for treatment of infection. The sensor comprises a screen-printed gold electrode, modified with an antibiotic-seeded hydrogel to monitor bacterial growth. Electrochemical growth profiles of the common microorganism, Escherichia coli (E. coli) (ATCC 25922) were measured in the presence and absence of the antibiotic streptomycin. Results show a clear distinction between the E. coli growth profiles depending on whether streptomycin is present, in a timeframe of ≈2.5 h (p < 0.05), significantly quicker than the current gold standard of culture-based antimicrobial susceptibility testing. These results demonstrate a clear pathway to a low cost, phenotypic and reproducible antibiotic susceptibility testing technology for the rapid detection of E. coli within clinically relevant concentration ranges for conditions such as urinary tract infections.
Design and production of a one-step 3D-printed functional electrochemical biosensor for efficient detection of dopamine and glucose in low-volume samples (100 μL). Glucose detection via ruthenium-mediated amperometry provides results in 60 seconds.
We present a low-cost, sensitive and specific DNA field-effect transistor sensor for the rapid detection of a common mutation to the tumour protein 53 gene (TP53). The sensor consists of a commercially available, low-cost, field-effect transistor attached in series to a gold electrode sensing pad for DNA hybridisation. The sensor has been predominantly optimised electrochemically, particularly with respect to open-circuit potentiometry as a route towards understanding potential (voltage) changes upon DNA hybridisation using a transistor. The developed sensor responds sensitively to TP53 mutant DNA as low as 100 nM concentration. The sensor responds linearly as a function of DNA target concentration and is able to differentiate between complementary and noncomplementary DNA target sequences.
Response of a ferroelectric capacitor to static temperature (~22 to 90°C) is presented. The sensor is based on ferroelectric ceramic lead zirconate titanate (PZT). The PZT sensor is a cheap, commercially available element used to provide a proof of concept for the initial investigation into using ferroelectric materials for the monitoring of static temperature. The capacitor response to temperature was measured using PZT capacitance changes recorded at 1 kHz. The capacitance was measured after the temperature had stabilised. We have found that the PZT capacitor responds linearly as a function of applied temperature, with a sensitivity ~53 pF/°C. Furthermore, to provide some initial electronics capable of measuring sensor capacitance in real time, the PZT element was attached to an Arduino Uno platform. Again, the sensor continues to respond linearly to temperature with a sensitivity of 146 pF/°C. The system developed paves the way for further work to be done on using ferroelectric materials for the monitoring of static temperature changes, for applications such as human body temperature measurement using a textile-based smart-shirt setup.