Recent Developments in Semiconducting Polymer Dots for Analytical Detection and NIR-II Fluorescence Imaging

Abstract

In recent years, semiconducting polymer dots (Pdots) have attracted enormous attention in applications from fundamental analytical detection to advanced deep-tissue bioimaging due to their ultrahigh fluorescence brightness with excellent photostability and minimal cytotoxicity. Pdots have therefore been widely adopted for a variety types of molecular sensing for analytical detection. More importantly, the recent development of Pdots for use in the optical window between 1000 and 1700 nm, popularly known as the "second near-infrared window" (NIR-II), has emerged as a class of optical transparent imaging technology in the living body. The advantages of the NIR-II region over the traditional NIR-I (700−900 nm) window in fluorescence imaging originate from the reduced autofluorescence, minimal absorption and scattering of light, and improved penetration depths to yield high spatiotemporal images for biological tissues. Herein, we discuss and summarize the recent developments of Pdots employed for analytical detection and NIR-II fluorescence imaging. Starting with their preparation, the recent developments for targeting various analytes are then highlighted. After that, the importance of and latest progress in NIR-II fluorescence imaging using Pdots are reported. Finally, perspectives and challenges associated with the emergence of Pdots in different fields are given.

Semiconducting polymer dots as fluorescent probes forin vitrobiosensing

“…Detection of specific biomolecules in the human body is essential for clinical diagnosis, especially for the early diagnosis of numerous diseases. 87 Chen et al prepared a C 60 -PAMAM-PFO nanocomposite via the electrostatic adsorption action between PFO Pdots and C 60 -PAMAM (polyamidoamine). 88 Based on the fact that H 2 O 2 could enhance the ECL intensity of the PFO system, this C 60 -PAMAM-PFO nanocomposite was able to achieve the quantitative detection of H 2 O 2 .…”

Nanomaterial-Based Dual-Emission Ratiometric Fluorescent Sensors for Biosensing and Cell Imaging

“…Wu et al found that Pdot-bioconjugates are much brighter (~30×) than QD-bioconjugates [ 71 ]. Additionally, Pdots also exhibit fast radiative rates and good photostability [ 72 , 73 ]. The PL mechanism of Pdots has been illustrated in the review by Zhu et al [ 57 ].…”

Carbon Dots for Intracellular Sensing

“…Until now, different kinds of fluorescent nanomaterials have been developed such as carbon dots (CDs), [1][2][3][4] silicon nanoparticles (NPs), [5][6][7][8][9][10][11][12][13] semiconductor quantum dots (QDs), [14][15][16][17][18] polymer dots, [19][20][21] dye-doped NPs, [19,22] and upconversion NPs. [23,24] Among them, CDs are considered as suitable fluorescent bioprobes due to their properties like good biosafety, facile preparation and modification, fascinating photoluminescence (PL), and excellent aqueous dispersity.…”