Enhanced single-particle brightness and photostability of semiconductor polymer dots by enzymatic oxygen scavenging system

Abstract

Semiconductor polymer dots (Pdots) are emerging as an excellent fluorescent probe in biology and medicine. However, the photostability of Pdots can't meet the requirements of long term single-particle imaging and tracking applications. Here we describe the enhanced single-particle brightness and photostability of Pdots by using an efficient enzymatic oxygen scavenging system (OSS). Pdots with particle diameters of 21 nm and 43 nm (PFBT21 and PFBT43) were prepared by a nanoprecipitation method. Single-particle imaging and photobleaching were performed to investigate the effect of OSS on the per-particle brightness and photostability of Pdots. Our results indicate that the single-particle brightness of the PFBT21 Pdots in OSS was enhanced nearly two times as compare to the PFBT21 Pdots in water. The photobleaching percentages of PFBT21 and PFBT43 in OSS were determined to be 29% and 33%, respectively. These values are decreased by 2-3 times as compared to those of the same Pdots in water, indicating the significantly improved photostability of Pdots by OSS. This study provides a promising approach for enhancing photostability of Pdots in long term single-particle tracking. 1. Introduction Single-particle fluorescence techniques have been widely used in biomedical engineering and biophotonics for investigation of cellular processes such as molecular transport, membrane dynamics, protein folding, and enzyme kinetics [1-8]. Optical super-resolution imaging modalities have been able to resolve subcellular structures and dynamic movements at the accuracy of the nanometer scale [9,10]. Bright and photostable probes are essential to achieve precise localization and high resolution in these optical imaging and tracking

Exciton Diffusion, Antenna Effect, and Quenching Defects in Superficially Dye-Doped Conjugated Polymer Nanoparticles

“…These observations are attributed to the presence of non-emissive exciton quenching sites or recombination centers (Q). , The number, nature, and location of Q centers appear to be highly dependent on several parameters associated with CPN preparation conditions. For example, the fluorescence lifetime (τ 0 CPN ) and quantum yield (Φ F0 CPN ) of our F8BT CPNs in the absence of dyes are different from those reported by some authors − but matches those reported by other authors. , The nature of Q sites has been associated with a number of entities such as polymer synthesis defects and charged species such as hole/electron–polarons. In particular, there are a significant number of publications describing efficient exciton quenching by charged species (polarons).…”

“…For example, the fluorescence lifetime (τ 0 CPN ) and quantum yield (Φ F0 CPN ) of our F8BT CPNs in the absence of dyes are different from those reported by some authors 33−35 but matches those reported by other authors. 36,37 The nature of Q sites has been associated with a number of entities such as polymer synthesis defects and charged species such as hole/electron−polarons. In particular, there are a significant number of publications describing efficient exciton quenching by charged species (polarons).…”

Emerging Designs of Activatable Photoacoustic Probes for Molecular Imaging

“…NIRabsorbing SPNs have emerged as a new class of photonic nanoagents for molecular imaging. 73,97,[135][136][137][138][139][140][141][142] By virtue of the high photostability and ROS resistance, SPNs were developed into activatable PA probes for imaging of ROS both in vitro and in vivo. 71 Poly(cyclopentadithiophene-alt-benzothiadiazole) (SP1) was transformed into the nanoprobe by co-precipitation with a ROS-sensitive NIR dye (IR775S) and lipid (Figure 6a).…”

“…ROS is a hallmark of many pathological processes ranging from acute and chronic bacterial infections to chronic diseases such as cancer, cardiovascular disease, and arthritis. ,, Imaging of ROS in living animals is challenging because many photonic imaging agents such as small-molecule dyes, QDs, and gold nanoparticles are not stable in the presence of ROS. NIR-absorbing SPNs have emerged as a new class of photonic nanoagents for molecular imaging. ,,− By virtue of the high photostability and ROS resistance, SPNs were developed into activatable PA probes for imaging of ROS both in vitro and in vivo . Poly­(cyclopentadithiophene- alt -benzothiadiazole) (SP1) was transformed into the nanoprobe by coprecipitation with a ROS-sensitive NIR dye (IR775S) and lipid (Figure a).…”

Highly Efficient Electrochemiluminescence of Cyanovinylene-Contained Polymer Dots in Aqueous Medium and Its Application in Imaging Analysis

“…In recent years, semiconductor polymer dots (Pdots) as a kind of new luminescent nanomaterial − have been widely used in biosensing, , in vivo imaging, , drug and gene delivery, , single particle tracing, , and super-resolution imaging . Pdots exhibit excellent optical properties, including extraordinary fluorescence brightness, ultrafast emission rate, and good photostability.…”