Attogram-level light-induced antigen-antibody binding confined in microflow

Abstract

The analysis of trace amounts of proteins based on immunoassays and other methods is essential for the early diagnosis of various diseases such as cancer, dementia, and microbial infections. Here, we propose a light-induced acceleration of antigen-antibody reaction of attogram-level proteins at the solid-liquid interface by tuning the laser irradiation area comparable to the microscale confinement geometry for enhancing the collisional probability of target molecules and probe particles with optical force and fluidic pressure. This principle was applied to achieve a 102-fold higher sensitivity and ultrafast specific detection in comparison with conventional protein detection methods (a few hours) by omitting any pretreatment procedures; 47–750 ag of target proteins were detected in 300 nL of sample after 3 minutes of laser irradiation. Our findings can promote the development of proteomics and innovative platforms for high-throughput bio-analyses under the control of a variety of biochemical reactions.

Label-Free Measurement of CD63 Positive Extracellular Vesicles Using Terahertz Chemical Microscopy

“…An antigen− antibody screen is a type of medical test that determines the presence of an antigen or antibody in a specimen based on the interaction between a specific antigen and antibody. 31 It can determine whether an immune response to a pathogen or other foreign substance is occurring. Figure 6(a) shows the imaging acquired with the buffer solution filled.…”

Light-induced acceleration of antigen-antibody reaction for detecting attogram-level proteins

“…We have proposed a new principle of light-induced acceleration of antigen-antibody reactions [10] to detect trace amounts of proteins at the solid-liquid interface by increasing the probability of collisions between target molecules and probe particles mediated by optical pressure (Fig. 1).…”

Ultrafast sensitivity-controlled and specific detection of extracellular vesicles using optical force with antibody-modified microparticles in a microflow system

“…33 Additionally, this light-matter interaction was further enhanced in a narrow space in a microfluidic channel using pressure-driven flow, which enabled the detection of femtogram-level proteins with photothermal probe particles 34 and accelerated the antigenantibody reaction of attogram-level proteins with non-thermal probe particles. 35 Thus, detection of proteins with high specificity would be expected using antibody-modified microparticles This journal is © The Royal Society of Chemistry 2023 without light absorption to avoid thermal damage while using the same narrow space. However, it is unclear whether the same method can be applied to the highly sensitive and rapid detection of biological nanoparticles expressing proteins on their surface, such as EV.…”

“…5) by solving the equation of motion based on the Euler method considering the discrete element model with optical force, interparticle contact force, drag force, gravitational force, and random force described in ref. 35. During the process of light-induced assembly, probe particles dispersed randomly were trapped by a dissipative force exerted by the large laser spot causing them to accumulate into a monolayer due to interaction with the channel wall (Fig.…”