Electrochemical Immunosensors for Quantification of Procalcitonin: Progress and Prospects

Abstract

Human procalcitonin (PCT) is a peptide precursor of the calcium-regulating hormone calcitonin. Traditionally, PCT has been used as a biomarker for severe bacterial infections and sepsis. It has also been recently identified as a potential marker for COVID-19. Normally, serum PCT is intracellularly cleaved to calcitonin, which lowers the levels of PCT (<0.01 ng/mL). In severe infectious diseases and sepsis, serum PCT levels increase above 100 ng/mL in response to pro-inflammatory stimulation. Development of sensors for specific quantification of PCT has resulted in considerable improvement in the sensitivity, linear range and rapid response. Among the various sensing strategies, electrochemical platforms have been extensively investigated owing to their cost-effectiveness, ease of fabrication and portability. Sandwich-type electrochemical immunoassays based on the specific antigen–antibody interactions with an electrochemical transducer and use of nanointerfaces has augmented the electrochemical response of the sensors towards PCT. Identification of a superior combination of electrode material and nanointerface, and translation of the sensing platform into flexible and disposable substrates are under active investigation towards development of a point-of-care device for PCT detection. This review provides an overview of the existing detection strategies and limitations of PCT electrochemical immunosensors, and the emerging directions to address these lacunae.

Electrochemical Sensing of Amoxicillin Drug-Assisted Uropathogenic E. coli Bacteria Using Gold Nanostructures—A Preliminary Study

“…Even though these methods are sensitive and selective, they require complex steps, skilled personnel, and time-consuming analysis (~48-72 h), which are not suitable for point-of-care diagnosis. The electrochemical detection method seems to be a convincing factor, with the ease of fabrication of electrodes and point-of-care devices [10,11]. Recently, a series of electrochemical immune/biosensors based on DNA [12][13][14], antibodies [15][16][17], aptamers [18][19][20][21], antimicrobial peptides [22], lectin [23], carbohydrates [24], and bacteriophages [25] for the detection of E. coli bacteria have been studied by using differential pulse voltammetry (DPV) [12,13,17,18], electrochemical impedance spectroscopy (EIS) [15,16,[19][20][21][22][23][24][25], amperometry [14], and quartz crystal microbalance [26].…”