Enrichment of Aggregation-Induced Emission Aggregates Using Acoustic Streaming Tweezers in Microfluidics for Trace Human Serum Albumin Detection

Abstract

Aggregation-dependent brightness (ADB) indirectly limits the in vitro performance of a pure aggregation-induced emission (AIE) probe in many ways; thus, controlling the aggregation state of the AIE probe is helpful for detecting an object of interest. Many studies are focused on the molecule design of the AIE probes, while less efforts have been made for the control of the aggregation of the AIEs. Here, an acoustic streaming tweezer (AST) generated using a gigahertz bulk acoustic wave resonator was applied to manipulate the aggregation status of the AIE probe and further enhance their performance for human serum albumin (HSA) detection. As the trapping size of the AST matches the working size of the AIE probe, the streaming can enrich and accumulate AIE nanoparticles, which then further trigger larger aggregates. Due to the ADB effect, the fluorescence intensity strongly increased, and thus, the detection limit of HSA was reduced to 0.5 μg/mL, which is low enough for kidney disease detection. Such an AST-assisted ADB strategy is potentially applicable to other AIE probes and can work as a portable choice for the biomedical detection.

Recent Advances in Acoustofluidics for Point‐of‐Care Testing

“…Moreover, acoustic streaming tweezers generated by SMR (Figure 5d) with a frequency of 2.295 GHz were successfully utilized for the trapping of aggregation-induced emission probes, and this probe trapping played an enormous role in human serum albumin detection, which was proven by the decrease in the detection limit (0.5 μg/L). [41] The Adrian Neild group placed a series of focused IDTs next to the microchannel wall, and the particles were pushed vertically and trapped behind the PDMS membrane. [42] Furthermore, the parallel IDT could generate travelling SAW to actuate the vibrational mode and form acoustic streaming with a single vortex in a capillary tube (Figure 5e), which trapped nanoparticles ranging in size from 80 to 500 nm.…”

Acousto-optofluidic 3D single cell imaging of macrophage phagocytosis of Pseudomonas Aeruginosa

“…9–11 LOC devices have been successful in performing a wide range of chemical and biological assays with high precision and efficiency. 12–15 Furthermore, due to their compatibility with microfabrication processes, LOC devices can easily incorporate a suit of powerful on-chip tools that further increase the range of control and manipulation such as, optical, 16–18 acoustic, 19–24 and other electrical 6,25,26 or mechanical 27 components. The highly controlled environment offered by microfluidic devices is ideal for studying phagocytosis as it allows researchers to investigate the effects of various parameters such as bacterial concentration, shear stress on cell function, etc.…”