The significance of developing a selective and sensitive sensor for quality control purposes is underscored by the prevalent use of kojic acid (KA) in cosmetics, pharmaceuticals, and food items. KA's utility stems from its ability to inhibit tyrosinase activity. However, the instability of KA and its potential adverse effects have created a pressing need for accurate and sensitive sensors capable of analyzing real samples.
View Article and Find Full Text PDFThis study proposed a CRISPR/Cas13a-powered electrochemical multiplexed biosensor for detecting SARS-CoV-2 RNA strands. Current SARS-CoV-2 diagnostic methods, such as reverse transcription PCR (RT-PCR), are primarily based on nucleic acid amplification (NAA) and reverse transcription (RT) processes, which have been linked to significant issues such as cross-contamination and long turnaround times. Using a CRISPR/Cas13a system integrated onto an electrochemical biosensor, we present a multiplexed and NAA-free strategy for detecting SARS-CoV-2 RNA fragments.
View Article and Find Full Text PDFA novel electrochemical sensor was constructed based on an enzyme-mediated physiological reaction between neurotransmitter serotonin per-oxidation to reconstruct dual-molecule 4,4'-dimeric-serotonin self-assembled derivative, and the potential biomedical application of the multi-functional nano-platform was explored. Serotonin accelerated the catalytic activity to form a dual molecule at the C4 position and created phenolic radical-radical coupling intermediates in a peroxidase reaction system. Here, 4,4' dimeric-serotonin possessed the capability to recognize intermolecular interactions between amine groups.
View Article and Find Full Text PDFBackground: Racial/ethnic minorities are at higher risk for severe COVID-19. This may be related to social determinants that lead to chronic inflammatory states. The aims of the study were to determine if there are racial/ethnic disparities with inflammatory markers and association of methylprednisolone to in hospital survival.
View Article and Find Full Text PDFWe have developed a powerful biosensing strategy for immobilizing histidine-tagged (His-Tag)-oriented recombinant nano-protein immobilization on a chemically modified glassy carbon electrode (GCE) surfaces via (S)-N-(5-amino-1-carboxypentyl)iminodiacetic acid (ANTA) acting as a chelating Ni centered interaction. Here, we introduce a label-free electro-sensor to quantify cortisol levels in saliva samples for point-of-care testing (POCT). The high specificity of the chemically modified GCE was established by genetically bio-engineered metal-binding sites on the selected recombinant apoferritin (R-AFTN) nano-protein to impart functionality to its surface and by coating the carbon surface with the self-assembled monolayers of 4-aminobenzoic acid (4-ABA) attached to ANTA groups complexed with Ni transition metal ions.
View Article and Find Full Text PDFSensitive and selective determination of protein biomarkers with high accuracy often remains a great challenge due to their existence in the human body at an exceptionally low concentration level. Therefore, sensing mechanisms that are easy to use, simple, and capable of accurate quantification of analyte are still in development to detect biomarkers at a low concentration level. To meet this end, we demonstrated a methodology to detect thrombin in serum at low concentration levels using polypyrrole (PPy)-palladium (Pd)nanoparticle-based hybrid transducers using liposomes encapsulated redox marker as a label.
View Article and Find Full Text PDFIn this report, we present an enzyme deposited Au electrode for an electrochemical measurement of acetylacetic acid (AcAc) in urine. The electrode has an immobilized layer of a mixture of D-β-hydroxybutyrate dehydrogenase (HBDH) and nicotinamide adenine dinucleotide (NADH) as sensing material to investigate its electroanalytical properties by means of cyclic voltammetry (CV). The modified electrodes are used for the detection of AcAc and present a linear current increase when the AcAc concentration increases.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
August 2021
Parathyroid hormone (PTH) is a hormone that plays a critical role in bone remodeling because it regulates the calcium levels. Either higher or lower than normal range of PTH release can cause serious metabolic disorders such as hyperparathyroidism or hypoparathyroidism. Therefore, the demand of highly sensitive monitoring sensor of PTH is on the rise.
View Article and Find Full Text PDFA label-free electrochemical impedimetric immunosensor for the detection of Triiodothyronine-a thyroid hormone that functions as the biomarker for monitoring for thyroid dysfunction was developed. The gold nanoparticle-modified electrode was employed to achieve the sensitive determination of Triiodothyronine at a low concentration level. The gold nanoparticle layer on the gold electrode was generated by chronoamperometry method and its resulting characteristics were investigated by scanning electron microscopy.
View Article and Find Full Text PDFMXene nanosheets of type TiCT were modified with β-hydroxybutyrate dehydrogenase and then used as a biosensor for amperometric sensing of β-hydroxybutyrate. The MXene and the nanocomposite were characterized by X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The MXene has a layered structure and proved to be an excellent immobilization matrix providing good compatibility with the enzyme β-hydroxybutyrate dehydrogenase.
View Article and Find Full Text PDFMicromachines (Basel)
November 2019
Here, we report a simple and effective method for capturing and displacement of gram-negative bacteria using aptamer-modified microbeads and acoustophoresis. As acoustophoresis allows for simultaneous washing and size-dependent separation in continuous flow mode, we efficiently obtained gram-negative bacteria that showed high affinity without any additional washing steps. The proposed device has a simple and efficient channel design, utilizing a long, square-shaped microchannel that shows excellent separation performance in terms of the purity, recovery, and concentration factor.
View Article and Find Full Text PDFDevelopment of a very sensitive biosensor is accompanied with an inevitable shrinkage in the linear detection range. Here, we developed an electrochemical biosensor with a novel methodology to detect microRNA-21 (miR21) at an ultralow level and broad linear detection range. A three-way junction RNA structure was designed harboring (i) a methylene blue (MB)-modified hairpin structure at its one leg to function as the sensing moiety and (ii) the other two legs to be further hybridized with barcode gold nanoparticles (MB/barG) as the signal amplifiers.
View Article and Find Full Text PDFMost clinical tests for biomarker detection require the support of a laboratory, and the results are usually slow, less sensitive, and lack the possibility for Point-of-Care (PoC) testing. Further, with the increasing demand for sensitive, portable, rapid, and low-cost devices for clinical PoC applications, innovative methods are crucial. Thus, we report on utilizing nanostructured gold-platinum (Au-Pt) hybrid electrodes as a PoC device for highly sensitive and selective PTH detection in human serum samples.
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