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According to the World Health Organization (WHO), cardiovascular disease (CVD) is the leading cause of death in the world every year. The design and development of biosensors for the detection of CVD markers could be one of the major contributions of the scientific community to society. In this context, acetic acid functionalized graphene quantum dots (fGQDs) were used as an interface for the electrochemical detection of cardiac Troponin I (cTnI). The interaction of cTnI with fGQDs for the early diagnosis of acute myocardial infarction was investigated using cyclic voltammetry (CV) and amperometry. The carbodiimide conjugation between the N-H group of cTnI and the functionalized COOH group on GQDs enabled the detection of cTnI biomarker. The same sensing mechanism was confirmed using Fourier Transform Infrared Spectrometry (FTIR). The fGQDs modified Au electrode showed remarkable electrocatalytic oxidation of cTnI with good stability and sensitivity over a linear range of 0.17 to 3 ng mL−1 and a low detection limit of 0.02 ng mL−1. Bland-Altman plots substantiate a bias between the intra-/inter-cTnI assay and calibrated cTnI assay with 95% limits of agreement (mean difference ± 1.96 SD). The aim of this study is to describe an innovative method to detect cardiac biomarker cTnI and provide preliminary data on its diagnostic capacity. At the same time, its applicability in clinical setting will have to be validated with a significant number of samples collected from patients.

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Foodborne and waterborne diseases caused by pathogens pose a serious threat to human life, and the detection of such pathogens in food, water, and beverages has gained paramount importance in view of the increasing number of pathogenic diseases in recent times. Standard and traditional analytical techniques employed for the recognition of deadly pathogens, including polymerase chain reaction‐based techniques, immunology‐based assays, culture and colony counting techniques, require several hours or perhaps even a few days for the results. All these techniques, despite being quite sensitive, are time‐intensive. Therefore, several researchers are focusing on the development of rapid pathogen detection techniques. Although the most advanced biosensing technologies exhibit potential approaches, significant research and testing is an urgent need to design innovative biosensors. Novel bioanalytical approaches for the recognition and quantification of target pathogens are being designed and developed to enhance the characteristics of biosensors, including rapid response, selectivity, and sensitivity. In this context, we not only provide an overview of the types of biorecognition elements employed for the detection of pathogens, but also discuss in detail the traditional approaches, biomolecular techniques, the latest advances in the detection and quantification of foodborne and waterborne pathogens, with particular emphasis on biosensors.

The traditional three-electrode electrochemical system used in the development of biosensors for detecting various biomarkers of interest necessitates the use of bulk electrodes, which precludes the deployment of handheld electrochemical devices in clinical applications. Affordable screen-printed carbon electrodes (SPCEs) modified with functional interfaces are being developed to enhance the sensitivity of a compact sensing system as a whole. In this work, SPCEs were fabricated on an overhead projection (OHP) sheet in three different active areas of 2 × 2, 3 × 3, and 4 × 4 mm2 using a screen printing technique, and then ∼2 nm sized graphene quantum dots (GQDs) were electrodeposited over the SPCE surface to add functionality for the detection of ultralow levels of one of the cardiac biomarkers, C-reactive protein (CRP). The proposed mediator-dependent voltammetric biosensor exhibited good sensitivity, a low detection limit, and a linear range of 2.45 μA ng–1 mL–1 cm–2, 0.036 ng mL–1, and 0.5–10 ng mL–1, respectively. The fabricated SPCE/GQDs/anti-CRP biosensor could rapidly detect CRP in less than 25 s. The intra- and interassays were performed with five sensor strips, which showed a minimum standard deviation of 1.85 and 2.8%, respectively. The SPCE/GQDs/anti-CRP electrode was used to detect CRP concentrations in a ringer lactate solution. Thus, the developed biosensor has all of the characteristics such as rapidity, inexpensive disposable electrodes, miniaturization, and a lower detection limit needed to evolve as a point-of-care (PoC) application.