A chemiluminescence resonance energy transfer aptasensor was fabricated for the detection of Staphylococcus aureus (S. aureus) with Co enhanced N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functional flowerlike gold nanoparticles (Co/ABEI-AuNFs) as donor and WS nanosheet as acceptor. In the presence of S. aureus, rolling circle amplification (RCA) can be started. Partially complementary sequence of RCA product functional ABEI-AuNFs (cDNA-ABEI-AuNFs) were then annealed to multiple sites of the RCA product to form duplex complex. This complex is less adsorbed onto the WS nanosheet, thus attenuating the quenching of ABEI-AuNFs chemiluminescence by WS nanosheet. In the absence of target S. aureus (and hence the absence of RCA and duplex formation), the free cDNA-ABEI-AuNFs is completely adsorbed onto the WS nanosheet and chemiluminescence quenching ensues. Under optimal conditions, the logarithmic correlation between the concentration of S. aureus and the CL signal was found to be linear within the range of 50 cfu/mL to 1.5 × 10 cfu/mL (R = 0.9913). The limits of detection of the developed method were found to be 15 cfu/mL for S. aureus. The selectivity and the capability of the biosensor in meat samples were also studied. Therefore, this simple and easy operation method can be used to detect S. aureus with high sensitivity and specificity.
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http://dx.doi.org/10.1016/j.aca.2016.12.045 | DOI Listing |
Luminescence
January 2025
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Two versatile yet simple methods, colorimetric and spectrofluorimetric, were utilized for the quantitation of nonchromophore neomycin using silver nanoparticles modified with fluorescein. Fluorescein was excited at 485 nm (emission at 515 nm); when it is deposited on the surface of silver nanoparticles, its fluorescence intensity at 515 nm is quenched. Neomycin restores the fluorescence level at 515 nm by displacing fluorescein from nanoparticle binding sites.
View Article and Find Full Text PDFBiomed Opt Express
January 2025
School of Physical Science and Information Technology, Liaocheng University, Liaocheng 252059, China.
Accurate and efficient determination of malachite green (MG) in aquaculture is crucial for ensuring environment and food safety. Herein, we present a dual-response fluorescence probe based on an Ag/PMMA/Eu nanocomposite for the sensitive detection of MG with low concentration and single droplet. The luminescence properties of the Ag/PMMA/Eu nanocomposite and the fluorescence resonance energy transfer (FRET) effect between Eu and MG are significantly improved due to the localized surface plasmon resonance (LSPR) effect.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Institute of Optoelectronic Materials and Devices, College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018 PR China. Electronic address:
Red light emitting perovskite quantum dot (PQD) glass, with narrow-band emission and excellent stability, holds great potential for applications in liquid crystal displays. However, its low photoluminescence quantum yield (PLQY) remains the biggest obstacle limiting its practical application. Additionally, the mechanism behind the enhancement of the PLQY is not well understood, which restricts the further improvement of the PLQY in red light emitting PQD glass.
View Article and Find Full Text PDFSmall
January 2025
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, P. R. China.
Developing single-particle nanocomposite with aqueous-phase orthogonal multicolor phosphorescence or multimodal luminescence holds great significance for optical coding, anti-counterfeiting encryption, bioimaging, and biosensing. However, it faces challenges such as a limited range of emission wavelengths and difficulties in controlling the synthesis process. In this work, a conjugate structure manipulation integrated luminophor confinement strategy is proposed to prepare carbon dots@upconversion nanoparticles (CDs@UCNPs) featuring aqueous-phase orthogonal multicolor room-temperature phosphorescence-upconversion luminescence (RTP-UCL) through wet-chemical synthetic methods.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, P. R. China.
Photoluminescence is one of the most intriguing properties of metal nanoclusters derived from their molecular-like electronic structure, however, achieving high photoluminescence quantum yield (PLQY) of metal core-dictated fluorescence remains a formidable challenge. Here, we report efficient suppression of the total structural vibrations and rotations, and management of the pathways and rates of the electron transfer dynamics to boost a near-unity absolute PLQY, by decorating progressive addition of cations. Specifically, with the sequential addition of Zn, Ag, and Tb into the 3-mercaptopropionic acids capped Au nanoclusters (NCs), the low-frequency vibration of the metal core progressively decreases from 144.
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