Quantum Dot Based Fluorescent Traffic Light Nanoprobe for Specific Imaging of Avidin-Type Biotin Receptor and Differentiation of Cancer Cells

Abstract

Sensitive and specific visualization of cell surface biotin receptors (BRs) a class of clinically important biomarkers, remains a challenge. In this work, a dual-emission ratiometric fluorescent nanoprobe is developed for specific imaging of cell surface avidin, a subtype of BRs. The nanoprobe comprises a dualemission quantum dot nanohybrid, wherein a silica-encapsulated red-emitting QD (rQD@SiO 2 ) is used as the "core" and greenemitting QDs (gQDs) are used as "satellites", which are further decorated with a new "love−hate"-type BR ligand, a phenanthroline−biotin conjugate with an amino linker. The nanoprobe shows intense rQD emission but quenched gQD emission by the BR ligand. Upon imaging, the rQD emission stays constant and the gQD emission is restored as cell surface avidin accrues. Accordingly, the overlaid fluorescence color collected from red and green emission changes from red to yellow and then to green. We refer to such a color change as a traffic light pattern and the nanoprobe as a fluorescent traffic light nanoprobe. We demonstrate the application of our fluorescent traffic light nanoprobe to characterize cancer cells. By the traffic light pattern, cervical carcinoma and normal cells, as well as different-type cancer cells including BR-negative colon cancer cells, BR-positive hepatoma carcinoma cells, breast cancer cells, and their subtypes, have been visually differentiated. We further demonstrate a use of our nanoprobe to distinguish the G2 phase from other stages in a cell cycle. These applications provide new insights into visualizing cell surface biomarkers with remarkable imaging resolution and accuracy.

Probing biotin receptors in cancer cells with rationally designed fluorogenic squaraine dimers

“…Alternatively, recent efforts resulted in development of hybrid nanoprobes to distinguish SMVT in cancer cells and 3D spheroids. [15][16][17][18] There is a particular demand in development of probes operating in far-red and near-infrared (NIR) region to image deeper in the tissues and potentially in vivo. [19][20][21][22] A number of concepts to generate uorogenic response to target-binding was developed in the last decade.…”

A Lab-in-a-Syringe Device Integrated with a Smartphone Platform: Colorimetric and Fluorescent Dual-Mode Signals for On-Site Detection of Organophosphorus Pesticides

“…The synthesis of amino-modified rQDs@SiO 2 was prepared according to previous studies. , Typically, 40 μL of red-emissive CdSe/ZnS QD solution (10 mg/mL) and 2 mL of ethanol were mixed in a glass vial and stirred for 10 min. Then, 2 μL of MPS solution was added into the above solution and stirred for 6 h. To obtain the SiO 2 shells, 150 μL of TEOS and 150 μL of NH 3 ·H 2 O were introduced, and the mixture solution reacted for another 12 h to obtain rQDs@SiO 2 .…”

Liposomal Spherical Nucleic Acid Scaffolded Site-Selective Hybridization of Nanoparticles for Visual Detection of MicroRNAs

“…More importantly, the recovery of green corona, in combination with the constant red core produces dual-emission-based ratiometric fluorescence. The ratiometric fluorescence can enhance the detection accuracy by offsetting a variety of systematic errors as well as improve the visual resolution by displaying distinct fluorescence-color changes. , By the use of our L-SNA–nanoparticle hybrid, traffic-light-type detection of circulating miRs was demonstrated below in a 96-well microplate setting.…”