Wettability with Aggregation-Induced Emission Luminogens

Tetraphenylethylene-indole as a novel fluorescent probe for selective and sensitive detection of human serum albumin (HSA) in biological matrices and monitoring of HSA purity and degradation

Human serum albumin (HSA) levels in serum and urine is a crucial biomarker for diagnosing liver and kidney diseases. HSA is used to treat various disorders in clinical practice and as an excipient in the production of vaccine or protein drug, ensuring its purity essential for patient safety. However, selective and sensitive detection of HSA remains challenging due to its structural similarity with bovine serum albumin (BSA) and the inherent complexity of biological matrices. This study presents a novel application of the tetraphenylethylene-indole (TPE-indo) fluorophore for the identification and quantification of HSA. The findings demonstrate that TPE-indo binds specifically to HSA in a 1:1 M ratio, thereby triggering its aggregation-induced emission (AIE) mechanism and producing a selective, sensitive, and rapid "turn-on" fluorescence response. The fluorescence intensity of TPE-indo exhibited minimal interference from proteins, amino acids, sugars, ions, and urine metabolites, and demonstrated a linear correlation with HSA concentration up to 60 μg/mL, with a limit of detection of 0.30 μg/mL. Furthermore, TPE-indo displays a markedly enhanced response to HSA in comparison to BSA, which can be ascribed to the distinct binding modes between TPE-indo and these two proteins. TPE-indo can be used to quantify HSA in serum, grade proteinuria samples, detect BSA adulteration in HSA samples, and real-time monitor HSA degradation processes. This study not only advances the development of efficient HSA detection methods but also highlights the significance of TPE-indo as a versatile tool for bioanalysis and clinical diagnosis.

A hydrogel-based ratiometric fluorescent sensor relying on rhodamine B labelled AIE-featured hyperbranched poly(amido amine) for heparin detection

The fluorescent flexible sensor for point-of-care quantification of clinical anticoagulant drug, Heparin (Hep), is still an urgent need of breakthrough. In this research, a hyperbranched poly(amido amine) (HPA) was decorated with tetraphenylethene (TPE) and Rhodamine B (RhB), constructing a ratiometric fluorescent sensor (TR-HPA) for Hep. When the sensor was exposed to Hep, the TPE units within the probe skeleton would aggregate, resulting in an increasing fluorescent emission at 483 nm. The 580 nm of fluorescence came from RhB enhance, simultaneously, due to the fluorescence resonance energy transfer. As a result, there are two good linear correlation between the fluorescence emission ratio (E483/E580) of TR-HPA and the Hep concentration over a range of 0-1.0 μM, with a low limit of detection of 3.0 nM. Furthermore, we incorporate the TR-HPA probe into a polyvinyl alcohol (PVA) hydrogel matrix to create a flexible fluorescent sensing system platform, denoted as TR-HPA/PVA. This approach offers a straightforward visual detection method by causing a fluorescence color change from pink to blue when trace amounts of Hep are present. The hydrogel-based fluorescent sensor streamlines the detection procedures for Hep in biomedical applications. It shows great potential in rapid and point-of-care human blood clotting condition monitoring, making it suitable for next-generation wearable medical devices.

Tunning Intermolecular Interaction of Peptide-Conjugated AIEgen in Nano-Confined Space for Quantitative Detection of Tumor Marker Secreted from Cells

Determining the expression level of biomarkers is crucial for disease diagnosis. However, the low abundance of biomarkers in the early stage makes the detection extremely difficult by traditional aggregation-induced emission (AIE)-based fluorescent probes. Here, by tuning the intermolecular interaction, a two steps-based MP/NPs-SLIPS sensing system is designed for ultrasensitive detection of the tumor marker matrix metalloproteinase-2 (MMP-2). During the sensing process, aggregation of AIE residual could be intensified through the electrostatic absorption by negatively charged nanoparticles (NPs), as well as the confined space formed by the self-assembly of NPs to photonic crystals (PCs) on slippery lubricant-infused porous substrates (SLIPS). The fluorescent signals obviously increased with a strengthened aggregation degree, which contributes to improved sensitivity. Thus, the limit of detection is decreased to 3.7 ng/mL for MP/NPs-SLIPS sensing system, which could be used for detecting the MMP-2 secreted by tumor cells directly. This strategy also demonstrated its potential applications as high-throughput detection devices and will be of significance for the ultrasensitive analysis of biomarkers.

A red-emitting cationic hyperbranched polymer: facile synthesis, aggregation-enhanced emission, large Stokes shift, polarity-insensitive fluorescence and application in cell imaging

A cationic hyperbranched polymer containing TPE units demonstrates bright and stable red-emission with AEE-characteristics and good performance in cell imaging.