Facile bimetallic co-amplified electrochemical sensor for folic acid sensing based on CoNPs and CuNPs

The function of chemical folic acid in calibration methods and neurodevelopmental disorders

Functional molecules have been attracting increasing attention in environmental and physiological studies. In particular, folic acid (FA) could be considered a key factor in estimating, adjusting, and making decisions in the treatment of neurodevelopmental disorders. It promotes the general significance and conceptual for considering FA molecular scientific research detections, which implies related advancement in both of biological structure and detection methods. Among these applications, the FA molecule acts as a coenzyme that incorporates carbon atoms and synthesizes purines and pyrimidines. Therefore, the calibration method has real applications and can be used as a sensing platform and for detection approaches, which conveys the internal relationship between the FA molecule and physiological characterization. This mini review briefly discusses multiple FA application fields and detection pathways and could supplement their utilization in anticipation of the onset of disease.

A homogeneous hybridization magnetic biosensor based on electric field assistance for ultrafast nucleic acid detection

Electrochemical biosensing is a sensitive strategy widely used in the field of nucleic acid detection. However, electrochemical biosensors generally involve time-consuming and labor-intensive probe immobilization processes. In this study, an electrochemical DNA biosensor based on homogeneous hybridization in solution was designed for nucleic acid detection without probe immobilization, which is different from most biosensors. The capture probe, detection probe, and target DNA were hybridized rapidly under an electric field to form a "sandwich" structure within 90 s, and the "sandwich" hybrid could be specifically coupled to streptavidin-modified magnetic beads within 5 min. Finally, the magnetic beads were enriched by using polypyrrole (PPy)/carbon nanotube (CNT)-modified magnetic electrodes and the signal was detected by differential pulse voltammetry (DPV). The magnetic biosensor constructed in this study could detect targets over a good linear dynamic range spanning 100 pM to 100 nM in 400 s, while those involving conventional hybridization methods always take 2 h or more. Because of the specific binding of streptavidin and biotin, this strategy showed high specificity. Taken together, the homogenous hybridization magnetic biosensor constructed with electric field assistance presents a potential diagnostic method for rapid DNA detection and provides a new idea for rapid nucleic acid detection in clinical practice.

An electrochemical sensor for purine base detection with ZIF-8-derived hollow N-doped carbon dodecahedron and AuNPs as electrocatalysts

In this paper, a novel electrochemical sensor was constructed for the detection of purine bases. Ultrafine carbide nanocrystals confined within porous nitrogen-doped carbon dodecahedrons (PNCD) were synthesized by adding molybdate to ZIF-8 followed by annealing. With MoC-based PNCDs (MC-PNCDs) as the carrier, gold nanoparticles (AuNPs) were deposited on the electrode surface via potentiostatic deposition as the promoter of electron transfer, forming a AuNPs/MC-PNCDs/activated glassy carbon electrode (AGCE) sensor. MC-PNCDs had a large specific surface area, which combined with the excellent electrocatalytic activity of AuNPs, synergistically improved the electrocatalytic activity. The morphology and structure of the electrode surface modifier were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray photoelectron spectroscopy, infrared spectroscopy, X-ray diffraction, nitrogen adsorption-desorption analysis, and electrochemical characterization. Under the optimal conditions, the linear detection range of guanine (G) and adenine (A) was 0.5-160.0 μM, and the detection limits (S/N=3) were 72.1 and 69.6 nM, respectively. AuNPs/MC-PNCDs/AGCE was successfully constructed, and was used to simultaneously detect G and A with high sensitivity and selectivity. Moreover, the sensor was successfully used to detect G and A in herring sperm DNA samples.