As part of our project of developing a new IR-based immunosensor, we investigated the functionalization of gold substrates with thin organic films containing biotin ligands. A two-step procedure was developed consisting of the chemisorption of short amine-terminated organosulfur compounds, followed by their reaction at the solid liquid interface with an activated ester derivative of biotin. Covalent binding of biotin to these attachment layers was assessed by Fourier transform infrared reflection-absorption spectroscopy (FT-IRRAS) and X-ray photoelectron spectroscopy (XPS). The interaction of activated biotin with alcohol- and carboxylic acid-terminated monolayers was also investigated, and, as expected, no binding occurred. Moreover, mixed layers of short alcohol- and amine-terminated thiolates were successfully constructed at the gold surfaces and were shown to be the most efficient for the covalent binding of biotin thanks to the blocking effect of the thioalcohol, which prevented direct adsorption of biotin to the gold surface. Copyright 2001 Academic Press.
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http://dx.doi.org/10.1006/jcis.2000.7362 | DOI Listing |
Talanta
January 2025
School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, 325035, China. Electronic address:
Hepatocellular carcinoma (HCC) stands as a grave illness characterized by elevated death rates. Early identification plays a vital role in improving patient survival. Herein, a novel split-type dual-mode biosensor featuring with near-infrared photoelectronchemical (PEC) and colorimetric sensing characteristics was developed for the high-performance detection of HepG2 cells.
View Article and Find Full Text PDFAnal Chem
January 2025
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
Timely and accurate detection of trace mycotoxins in agricultural products and food is significant for ensuring food safety and public health. Herein, a deep learning-assisted and entropy-driven catalysis (EDC)-Argonaute powered fluorescence single-particle aptasensing platform was developed for ultrasensitive detection of fumonisin B (FB) using single-stranded DNA modified with biotin and red fluorescence-encoded microspheres as a signal probe and streptavidin-conjugated magnetic beads as separation carriers. The binding of aptamer with FB releases the trigger sequence to mediate EDC cycle to produce numerous 5'-phosphorylated output sequences, which can be used as the guide DNA to activate downstream Argonaute (Ago) for cleaving the signal probe, resulting in increased number of fluorescence microspheres remaining in the final reaction supernatant after magnetic separation.
View Article and Find Full Text PDFFront Cell Dev Biol
January 2025
Department of Physiology, Immunology and Pathophysiology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.
Introduction: Cytomegalovirus (CMV) infection reorganizes early endosomes (EE), recycling endosome (RE), and trans-Golgi network (TGN) and expands their intermediates into a large perinuclear structure that forms the inner part of the cytoplasmic assembly complex (AC). The reorganization begins and results with the basic configuration (known as pre-AC) in the early (E) phase of infection, but the sequence of developmental steps is not yet well understood. One of the first signs of the establishment of the inner pre-AC, which can be observed by immunofluorescence, is the accumulation of Rab10.
View Article and Find Full Text PDFViruses
December 2024
Departmento of Pathology, Evandro Chagas Institute, Ministry of Health, Ananindeua 67030-000, PA, Brazil.
Necroptosis is a regulated form of cell death implicated in several pathological conditions, including viral infections. In this study, we investigated the expression and correlation of necroptosis markers MLKL, RIP1 and RIP3 in human liver tissue from fatal cases of yellow fever (YF) using immunohistochemistry (IHC). The liver samples were obtained from 21 YF-positive individuals and five flavivirus-negative controls with preserved liver parenchymal architecture.
View Article and Find Full Text PDFRNA Biol
December 2025
Department of Cell and Molecular Biology, Biomedical Centre, Uppsala University, Uppsala, Sweden.
We show that a small biotin-binding RNA aptamer that folds into a pseudoknot structure acts as a substrate for bacterial RNase P RNA (RPR) with and without the RNase P C5 protein. Cleavage in the single-stranded region in loop 1 was shown to depend on the presence of a RCCA-motif at the 3' end of the substrate. The nucleobase and the 2'hydroxyl at the position immediately 5' of the cleavage site contribute to both cleavage efficiency and site selection, where C at this position induces significant cleavage at an alternative site, one base upstream of the main cleavage site.
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