Phenotyping of Methicillin-ResistantStaphylococcus aureusUsing a Ratiometric Sensor Array

Abstract

Chemical tools capable of classifying multidrugresistant bacteria (superbugs) can facilitate early-stage disease diagnosis and help guide precision therapy. Here, we report a sensor array that permits the facile phenotyping of methicillinresistant Staphylococcus aureus (MRSA), a clinically common superbug. The array consists of a panel of eight separate ratiometric fluorescent probes that provide characteristic vibration-induced emission (VIE) profiles. These probes bear a pair of quaternary ammonium salts in different substitution positions around a known VIEgen core. The differences in the substituents result in varying interactions with the negatively charged cell walls of bacteria. This, in turn, dictates the molecular conformation of the probes and affects their blue-to-red fluorescence intensity ratios (ratiometric changes). Within the sensor array, the differences in the ratiometric changes for the probes result in "fingerprints" for MRSA of different genotypes. This allows them to be identified using principal component analysis (PCA) without the need for cell lysis and nucleic acid isolation. The results obtained with the present sensor array agree well with those obtained using polymerase chain reaction (PCR) analysis.

Multimode Stimuli-Responsive Room-Temperature Phosphorescence Achieved by Doping Butterfly-like Fluorogens into Crystalline Small-Molecular Hosts

“…Specifically, DPACs display intrinsic blue emission stemmed from their saddle-shaped conformations in the confined state and abnormal orange-red fluorescence originated from the planar conformation in the unconfined state, with large Stokes shift of up to 200 nm. − It was later proven by a series of theoretical calculations and experiments that the orange-red emission is caused by the intramolecular bent-to-planar vibrations of the phenazine ring. Therefore, this phenomenon was named as vibration-induced emission (VIE). − Up until now, the DPAC derivatives have been widely explored for various purposes by virtue of their large Stokes shift and dual emissions. − For example, DAPC derivatives have been developed to probe physical parameters such as temperature, , viscosity, and moisture, to monitor physical processes such as self-assembly, gelation, and microphase separation in real time, to detect chemical and biological species such as metal ions, , dicarboxylate dianions, , and glucose, to detect and block influenza viruses, , to distinguish bacteria, to conduct three-photon bioimaging, and to construct mitochondria-specific photosensitizers . To the best of our knowledge, the overwhelming majority of research studies related to VIE are based on the dual-fluorescence emission characteristics, but the phosphorescence properties of phenazine and its derivatives have received little attention. , Nevertheless, the N , N′ -disubstituted-dihydrodibenzo­[ a , c ]­phenazine derivatives not only have the above-mentioned unique dual fluorescence emissions but also, what is even more important, that their fluorescence is easily affected by the surrounding environment, such as temperature, viscosity, etc., as a result of their flexible conformations.…”

“… 38 − 45 Up until now, the DPAC derivatives have been widely explored for various purposes by virtue of their large Stokes shift and dual emissions. 46 − 66 For example, DAPC derivatives have been developed to probe physical parameters such as temperature, 50 , 51 viscosity, 52 and moisture, 53 to monitor physical processes such as self-assembly, 54 gelation, 55 and microphase separation 56 in real time, to detect chemical and biological species such as metal ions, 57 , 58 dicarboxylate dianions, 59 , 60 and glucose, 61 to detect and block influenza viruses, 62 , 63 to distinguish bacteria, 64 to conduct three-photon bioimaging, 65 and to construct mitochondria-specific photosensitizers. 66 To the best of our knowledge, the overwhelming majority of research studies related to VIE are based on the dual-fluorescence emission characteristics, but the phosphorescence properties of phenazine and its derivatives have received little attention.…”

Selective FRET nano probe based on carbon dots and naphthalimide–isatin for the ratiometric detection of peroxynitrite in drug-induced liver injury

“…[25][26][27] All these potential advantages make the detection method based on uorescent probes a hot area of research for development. [28][29][30][31][32][33][34][35][36][37] In general, uorescent probes respond to target analytes based on specic interactions to generate changes in uorescence intensity. [38][39][40][41][42][43][44] However, detection methods based on emission intensities at a single wavelength are not reliable and accurate enough due to the interference from the environment and probe concentrations.…”

PEC-SERS Dual-Mode Detection of Foodborne Pathogens Based on Binding-Induced DNA Walker and C3N4/MXene-Au NPs Accelerator

“…Foodborne bacterial infections and contaminations have emerged as a significant public health concern, posing a serious threat to human health and the global economy. Among various species, Staphylococcus aureus ( S. aureus ) is one of the most widely distributed species, which can easily lead to toxic and infectious shock syndromes. , However, the concentration of S. aureus is extremely low in the early stages of infection. Therefore, rapid and accurate detection of S. aureus is a key and effective tool to diminish the risk of infection and prevent related diseases.…”