A detection system for theophylline that combined the recognition properties of an aptamer and the plasmonic response of gold nanoparticles (AuNPs) is presented. The aptamer was used as a linker for AuNPs functionalized with complementary sequences to the aptamer (DNA-AuNPs), producing supramolecular complexes that disassemble when exposed to theophylline due to aptamer binding. The detection event was reported as a change in the AuNPs plasmonic peak and intensity. Addition of a spacer on the DNA immobilized on the AuNPs facing the aptamer binding site improved the aggregates' response, doubling the detection range of system response to theophylline. Modification of the oligonucleotides immobilized on the AuNPs that reduced the interparticle distance in the aggregated state suppressed their response to theophylline and addition of the spacer recovered it. This work demonstrated that the design of oligonucleotides immobilized on the AuNPs could be used to improve their plasmonic response without affecting aptamer performance.
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http://dx.doi.org/10.1016/j.bios.2010.04.049 | DOI Listing |
J Hazard Mater
December 2024
College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China; Jiaxing Key Laboratory of Molecular Recognition and Sensing, China. Electronic address:
Small-molecule biotoxins are frequently founded in grains, corns, peanuts, and different kinds of aquatic products, and they are harmful to human health. Lateral flow immunoassays (LFIAs) have been widely used for on-site detection of small-molecule biotoxins. However, most of the reported LFIAs approaches are signal-off type because each small-molecule biotoxin only has one antigen binding site due to the small size of the molecule.
View Article and Find Full Text PDFActa Pharm Sin B
November 2024
Institute of Pharmaceutical Analysis, College of Pharmacy/State Key Laboratory of Bioactive Molecules and Druggability Assessment/International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Ministry of Education (MOE) of China, Jinan University, Guangzhou 510632, China.
The dynamic tracking of antibody‒drug conjugates (ADCs) in serum is crucial. However, a versatile bioanalytical platform is lacking due to serious matrix interferences, the heterogeneity and complex biotransformation of ADCs, and the recognition deficiencies of traditional affinity technologies. To overcome this, a multiepitope recognition technology (MERT) was developed by simultaneously immobilizing CDR and non-CDR ligands onto MOF@AuNPs.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, LiuFang Campus, No.206, Guanggu 1st road, Donghu New & High Technology Development Zone, Wuhan 430205, Hubei Province, PR China. Electronic address:
This study aims to prepare a monodisperse catalyst with a space-confined strategy, employing cellulose beads (CBs) as a carrier. Amino functionalized cellulose beads (ACBs) were prepared by grafting polyethyleneimine into the space of CBs via glutaraldehyde cross-linking. The in-situ reduction method was successfully employed to confine monodisperse ultrasmall gold nanoparticles (AuNPs) within the amino functionalized cellulose beads (AuNPs@ACBs) matrix.
View Article and Find Full Text PDFMikrochim Acta
December 2024
Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Military Medical Sciences Academy, Academy of Military Science, Tianjin, 300050, China.
A dual-mode immunoassay method was developed for colorimetric and fluorescence detection of aflatoxin B1 (AFB1) based on streptavidin-induced gold nanoparticle aggregation (AuNP@SA). AuNP-modified streptavidin-biotin labeling AFB1 complete antigen aggregations (AuNP@SA@Bio-BSA-AFB1) were synthesized as the competitive binding and dual-mode probe. AuNP@SA@Bio-BSA-AFB1 aggregations possessed high colorimetric and fluorescence quenching intensities.
View Article and Find Full Text PDFBioelectrochemistry
November 2024
Life Science and Chemistry College, Hunan University of Technology, Zhuzhou 412007, China. Electronic address:
Early cancer diagnosis is paramount for enhancing treatment efficacy, extending patient survival, and improving the quality of life. We developed a highly sensitive electrochemical biosensor for the detection of target DNA (tDNA) associated with gastric cancer. This advancement integrates dual signal amplification strategies: bio-barcode amplification (BCA) and surface-initiated enzyme polymerization (SIEP), with copper nanoclusters (CuNCs) serving as signal labels.
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