Detection of Urinary Albumin Using a “Turn‐on” Fluorescent Probe with Aggregation‐Induced Emission Characteristics

Abstract

Human serum albumin (HSA) is a broadly used biomarker for the diagnosis of various diseases such as chronic kidney disease. Here, a fluorescent probe TC426 with aggregation‐induced emission (AIE) characteristics is reported as a sensitive and specific probe for HSA. This probe is non‐emissive in aqueous solution, meanwhile it shows bright fluorescence upon interacting with HSA, which makes it applicable in detecting HSA with a high signal to noise ratio. Besides, the fluorescence of TC426 exhibits a high linear correlation with the concentration of albumin in the range of microalbumin (20–200 mg/L), which has a significant importance for the early diagnosis of glomerulus related diseases. Compared with previously reported HSA probes TPE‐4TA and BSPOTPE, TC426 shows comparable anti‐interference ability towards creatinine and other major components in urine but is excited by a longer excitation wavelength at the visible light range. Finally, with the established assay, TC426 shows excellent performance in detecting HSA in real human urine, indicating its great potential in practical urinalysis.

Solid-State Nanochannel with Multiple Signal Outputs for Furin Detection Based on the Biocompatible Condensation Reaction

“…After being reacted with furin and TCEP, activated CTC could link end-to-end to form an oligomer. The aggregated state would impede the phenyl rotation in AIEgen, leading to the enhanced fluorescence (Figure f). , Therefore, this nanochannel device displayed the selective and sensitive sensing ability for furin by triggering the blockage of nanochannels.…”

Common Pitfalls and Recommendations for Using a Turbidity Assay to Study Protein Phase Separation

“…However, imaging techniques to directly visualize the morphology of protein particles are necessary upon measuring protein liquid-to-liquid phase separation due to its highly dynamic and reversible nature. In addition, we expected that new protein aggregation sensors − ,− ,− and novel fluorogenic chemistries , can potentially assist us in resolving the protein phase separation process in detail. Overall, we present experimental recommendations that researchers may take into consideration when using the turbidity assay to study protein phase separation and further reveal the biochemical mechanism-of-action of these currently incurable protein conformational diseases.…”

“…The multistep protein phase separation process involving protein unfolding, misfolding, and aggregation poses technical challenges to visualize, resolve, and regulate these species of no defined 3-dimensional structures . Classic analytical methods to study protein misfolding and aggregation include biochemical fractionation to separate protein species on the basis of their different solubility and sizes. , Fluorescence spectroscopic and microscopic analyses explore protein conformation-sensitive dyes, such as Congo red, Thioflavin T, and other organic fluorophores developed in recent years, to selectively resolve phase separated proteins at different states. − To further analyze the protein phase separation process in live cells, numerous state-of-the-art optical methods have been optimized, including fluorescence resonance energy transfer (FRET) imaging, fluorescence recovery after photobleaching (FRAP) imaging, and stimulated Raman scattering imaging. − Microscopic methods using atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cryo-electron microscopy (cryo-EM), etc. − provide a direct observation or even an atomic resolution of the aggregated proteins. Single molecule fluorescence and mass spectrometry analyses can further resolve the intermolecular interactions during the protein phase separation process. − …”

Near-Infrared-Emissive AIE Bioconjugates: Recent Advances and Perspectives

“…As one of the most important biomacromolecules in the living systems [69], proteins play an important role in the construction of the cell structure and substance and messages delivery and can serve as biosensors by modification with functional materials [70]. Benefiting from the advantages of NIR AIEgens, the bioconjugation between NIR AIEgens and specific proteins is considered as an appropriate method to manufacture smart biosensors, and numerous NIR AIEgen-protein based biosensors have been reported over the past few years (Figure 5a) [71][72][73][74][75].…”