From Theory to Reality

We report an aptamer-based SARS-CoV-2 salivary antigen assay employing only low-cost reagents ($3.20/test) and an off-the-shelf glucometer. The test was engineered around a glucometer as it is quantitative, easy to use, and the most prevalent piece of diagnostic equipment globally, making the test highly scalable with an infrastructure that is already in place.

A reagent-free electrochemical aptasensor with a nanocomposite antifouling layer for sensitive and continuous detection of cortisol in human serum. A thiolated, methylene blue (MB)- tagged conformation-switching aptamer was immobilized over a gold nanowire (AuNW) nanocomposite to capture cortisol and generate a signal proportional to the cortisol concentration. The signal is recorded through differential pulse voltammetry (DPV) and chronoamperometry.

A capacitive aptasensor for detecting the malaria biomarker, Plasmodium falciparum glutamate dehydrogenase (PfGDH), directly in human serum samples developed. A thiolated ssDNA aptamer (NG3) that binds specifically to PfGDH antigen with high affinity (Kd = 79 nM) was used to develop the aptasensor. The aptasensor produced capacitance response at an optimized frequency of 2 Hz in a non-Faradaic electrochemical impedance based signal transduction platform.

Here, we report an ECAD assay for detecting SARS-CoV-2 in clinical samples. The displacement of aptamer from immobilized antisense onto the antigen was first confirmed through a fluorescence resonance energy transfer (FRET) study.  Then, an electrochemical sensor was engineered based on methylene blue (MB) differential response for ssDNA and dsDNA. Antigen protein, cultured virus, and clinical saliva specimens were used to assess the performance of the N and S protein.

an aptamer-based field effect transistor (aptaFET) biosensor, developed by using an extended gate field effect transistor with inter-digitated gold microelectrodes (IDμE) for the detection of the malaria biomarker Plasmodium falciparum glutamate dehydrogenase (PfGDH) in serum samples. A 90 mer long ssDNA aptamer (NG3) selective to PfGDH was used in the aptaFET to capture the target protein

we report the detection of pan malaria and P. falciparum species using a dye-based reaction catalyzed by the biomarker enzymes Plasmodium lactate dehydrogenase (PLDH) and Plasmodium falciparum glutamate dehydrogenase (Pf GDH), respectively, through instrument-based and instrument-
free approaches