Dual fluorescence nanoconjugates for ratiometric detection of reactive oxygen species in inflammatory cells

Abstract

Reactive oxygen species (ROS) are largely produced under pathological situations. To understand the etiology of disease, it is urgent to develop efficacious probes for detecting ROS. Herein, a novel nanoconjugate detection system constructed from gold clusters (AuNCs) and quantum dots (QDs) for fluorescence ratiometric-sensing ROS was reported. Upon interacting with ROS, the red emission fluorescence (645 nm from QDs) in the detection system gradually decreased, while the green fluorescence (480 nm from AuNCs) changed little. The fluorescence ratio at the 2 wavelengths (I /I ) was linearly correlated with the ROS, which could be used for the real-time ratiometric detection of ROS. The developed nanoconjugates could be applied to monitor the ROS in inflammatory cells for its ability of generating abundant ROS and uptaking ability to nanoparticles. The stimulated ROS in inflammatory cells were monitored by AuNC-QD and the results were consistent with the traditional 2', 7'-dichlorofluorescin diacetate method, confirming the reliability of the developed method. Featured with the merits of higher photostability, low background, high accuracy of ratiometric detection, the AuNC-QD conjugate demonstrated its potential to be the probe for real-time ROS detection in inflammatory cells.

The combined effect of dichloroacetate and 3-bromopyruvate on glucose metabolism in colorectal cancer cell line, HT-29; the mitochondrial pathway apoptosis

“…In all wells (90% confluence) treated with 3Br-P, DCA and 5-FU alone and/or combined together, cells were washed twice with PBS, followed by staining with 10 μM DCFH-DA for 45 min. Then, after 2, 4, 8, and 12 h, the formation of fluorescent-oxidized DCF was measured by fluorimetry (535 nm excitation and 635 nm emission) [ 20 ].…”

The Combined Effect of Dichloroacetate and 3-Bromopyruvate in Colorectal Cancer Cell Line, HT-29; The Mitochondrial Pathway Apoptosis

“…In all wells (90% con uence) treated with 3Br-P, DCA and 5-FU alone and/or combined together, cells were washed twice with PBS, followed by staining with 10 µM DCFH-DA for 45 min. Then, after 2, 4, 8, and 12 hours, the formation of uorescent-oxidized DCF was measured by uorimetry (535 nm excitation and 635 nm emission) (19).…”

Metal Nanoclusters–Based Ratiometric Fluorescent Probes from Design to Sensing Applications

“…The nanocomplex provides a sensitive sensor for rapid imaging of hROS signaling with high selectivity and contrast. Subsequently, Gu and co‐workers reported a nanoconjugate detection system for the determination of ROS based on the differential response from Au NCs and QDs . Whereas the red emission at 645 nm from QDs was strongly quenched by ROS, green‐emitting at 480 nm of Au NCs proved inert to quenching.…”