Search

Detecting disease-related biomarkers is of great significance for disease diagnosis and therapy. In this work, we develop an ultrasensitive surface-enhanced Raman scattering (SERS) biosensor for the detection of an acute myocardial infarction-related miRNA (miR-133a) using composition-adjustable hollow Ag/Au nanosphere-based SERS probes coupled with the target-catalyzed hairpin assembly (CHA) strategy. Bimetallic probes displaying high stability and a strong surface plasmon resonance effect were synthesized with a controllable ratio of silver and gold by a galvanic replacement method and then captured by a duplex linker produced in the CHA process to accomplish signal amplification. In this way, the target miR-133a can be detected in a wide linear range with a detection limit of 0.306 fM and high selectivity over other miRNAs expressed in human hearts. Practical applications in human blood samples reveal the strong anti-interference ability and ideal sensitivity of our developed sensing platform in physiological environments, benefiting its potential biomedical applications.

Surface-enhanced resonance Raman scattering (SERRS) is not realized for most molecules of interest. Here, we developed a new SERRS platform for the fast and sensitive detection of 2,4,6-trinitrotoluene (TNT), a molecule with low Raman cross section. A cationic surfactant, cetylpyridinium chloride (CPC) was modified on the surface of silver sols (CP-capped Ag). CPC not only acts as the surface-seeking species to trap sulfite-sulfonated TNT, but also undergoes complexation with it, resulting in the presence of two charge-transfer bands at 467 and 530 nm, respectively. This chromophore absorbs the visible light that matches with the incident laser and plasmon resonance of Ag sols by the use of a 532.06 nm laser, and offered large resonance Raman enhancement. This SERRS platform evidenced a fast and accurate detection of TNT with a detection limit of 5×10−11 M under a low laser power (200 μW) and a short integration time (3 s). The CP-capped Ag also provides remarkable sensitivity and reliable repeatability. This study provides a facile and reliable method for TNT detection and a viable idea for the SERS detection of various non-resonant molecules. [ABSTRACT FROM AUTHOR]

Difficult, but excellent surface‐enhanced resonance Raman scattering (SERRS) provides a fast and accurate method for the detection of ultra‐small traces of trinitrotoluene (TNT) under low laser power and in a short integration time. In their Full Paper on page 8789 ff., H. L. Liu, L. B. Yang, J. H. Liu et al. describe how cetylpyridinium chloride modified on Ag sols not only acts as the surface‐seeking species to trap sulfite‐sulfonated TNT, but also undergoes complexation with the sulfonated TNT, resulting in the appearance of two charge‐transfer bands at 467 and 530 nm. [ABSTRACT FROM AUTHOR]