- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Colorimetric Analysis of Carcinoembryonic Antigen Using Highly Catalytic Gold Nanoparticles-Decorated MoS <sub/>2</sub> Nanocomposites
摘要： Sensitive detection of carcinoembryonic antigen (CEA) is very important for early detection and cancer therapy monitoring. We utilized the highly catalytic activity of MoS2-gold nanoparticles (MoS2-AuNPs) nanocomposites to construct a colorimetric immunoassay for CEA detection, which could catalyze sodium borohydride (NaBH4) to reduce 4-nitrophenol (4-NP) and make the yellow solution colorless. MoS2-AuNPs nanocomposites could e?ciently load antibodies (Ab1 and Ab2) because of their good biocompatibility and high adsorption ability, forming Ab1-MoS2-AuNPs nanoprobes for capturing CEA and Ab2-MoS2-AuNPs nanoprobes for catalytic reaction. It should be pointed out that Ab2-MoS2-AuNPs nanoprobes retained high catalytic activity because no blocking agent was used to block the catalytic sites. After the formation of the classical “sandwich” structure, parts of Ab2-MoS2-AuNPs nanoprobes remained in the supernatant after centrifugation, making the catalytic reaction occur and obtaining a colorless solution. As expected, a linear function between absorbance peak intensity and the logarithm of 5 pg/mL?10 ng/mL CEA was observed, and the detection limit was obtained as 0.5 pg/mL. This colorimetric immunosensor showed acceptable selectivity and repeatability for CEA detection, which could be successfully employed to detect CEA in serum.
关键词： nanoprobe,colorimetric,carcinoembryonic antigen,molybdenum disul?de,immunosensor
更新于2025-09-04 15:30:14
-
Perylene-Based Fluorescent Nanoprobe for Acid-Enhanced Detection of Formaldehyde in Lysosome
摘要： Formaldehyde (FA), as a reactive carbonyl species, is extremely hazardous to human health if its concentration is above normal level. In live cells, lysosome is a main organelle to generate endogenous FA. Thus, the design of facile, stable and sensitive probes for the detection of FA in lysosome is essential. Herein, a self-assembled fluorescent nanoprobe based on homoallylamino substituted perylene (P-FA) has been developed for FA detection in lysosome. P-FA can react with FA along with emission color change from blue to green. P-FA exhibited high sensitivity and selectivity to FA in DMSO solution. In aqueous solution, P-FA self-assembled into uniform sphere-like nanoparticle as a fluorescent nanoprobe. Furthermore, the reaction between the nanoprobe and FA was greatly facilitated at pH 4-5, leading to a lower detection limit (0.96 μM at pH 5) than that in DMSO. In live cells, P-FA nanoprobe achieved long-term tracking of lysosome (over 12 h). The fluorescent nanoprobe was then used for both exogenous and endogenous FA detection. Our work provides a facile and effective strategy for the detection of FA in lysosome.
关键词： Weak Acidity,Perylene,Formaldehyde Detection,Lysosome,Fluorescent Nanoprobe
更新于2025-09-04 15:30:14
-
Voltammetric immunoassay of human IgG based on the release of cadmium(II) from CdS nanocrystals deposited on mesoporous silica nanospheres
摘要： The authors describe a nanocomposite that was obtained by in-situ deposition of CdS nanocrystals on mesoporous silica nanospheres (MSNs), and its use in an electrochemical immunoassay of human immunoglobulin G (HIgG). The MCN/CdS nanocomposite was covalently modified with the antibodies against HIgG and then employed in a voltammetric immunoassay at antibody-functionalized magnetic beads. Through sandwich immunoreaction, the MCN/CdS nanoprobes are quantitatively captured onto the magnetic beads where numerous Cd(II) ions are released in an acidic solution. The Cd(II) can be detected by anodic stripping voltammetry at a typical working potential of ?0.78 V (vs. Ag/AgCl). In combination with the high loading of CdS on MSNs, the use of the stripping voltammetric analysis renders the method high sensitivity. A wide linear range varying from 0.01 to 100 ng mL?1 is obtained for HIgG detection with a lower detection limit at 2.9 pg mL?1. In addition, the preparation of the nanoprobe is inexpensive. The magnetic bead-based assay does not require complex manipulations. Therefore, this method is deemed to possess a wide scope in that it may be applied to other immunoassays.
关键词： Magnetic beads,Anodic stripping voltammetry,Immunosensor,Nanoprobe,Signal amplification
更新于2025-09-04 15:30:14