Integration and Quantitative Visualization of 3,3′,5,5′-Tetramethylbenzidine-Probed Enzyme-Linked Immunosorbent Assay-like Signals in a Photothermal Bar-Chart Microfluidic Chip for Multiplexed Immunosensing

Abstract

The photothermal effect shows significant promise for various biomedical applications but is rarely exploited for microfluidic lab-on-a-chip bioassays. Herein, a photothermal barchart microfluidic immunosensing chip, with the integration of the conventional 3,3′,5,5′-tetramethylbenzidine (TMB)-probed enzyme-linked immunosorbent assay (ELISA)-like system, was developed based on exploiting the photothermal pumping technique for visual bar-chart microfluidic immunosensing. Both the sandwich ELISA-like system and the photothermal pumping protocol were integrated into a single photothermal bar-chart chip. On-chip immunocaptured iron oxide nanoparticles catalyzed the oxidation of the chromogenic substrate, TMB, to produce a sensitive photothermal and chromogenic dual-functional probe, oxidized TMB. As the result of heat generation and the subsequent production of elevating vapor pressure in the sealed microfluidic environment, the on-chip near-infrared laser-driven photothermal effect of the probe served as a dose-dependent pumping force to drive the multiplexed quantitative display of the immunosensing signals as visual dye bar charts. Prostate-specific antigen as a model analyte was tested at a limit of detection of 1.9 ng•mL −1 , lower than the clinical diagnostic threshold of prostate cancer. This work presents a new perspective for microfluidic integration and multiplexed quantitative bar-chart visualization of the conventional TMBprobed ELISA signals possibly by means of an affordable handheld laser pointer in a lab-on-a-chip format.

Flap Endonuclease-Induced Steric Hindrance Change Enables the Construction of Multiplex and Versatile Lateral Flow Strips for DNA Detection

“…The oligonucleotide sequences were from ref 43 and were pre-tested for orthogonality to ensure negligible hetero-dimer (Δ|G| < 10) using OligoAnalyzer Tool (online software of Integrated DNA Technologies, Inc). Flaphps and HPs with five kinds of flap lengths (10,12,14,16, and 18 nt) were used to investigate the performance of the FISH-LFS.…”

“…Point-of-care testing (POCT) , of DNA is an important way for rapid pathogen detection, in particular at source-limited regions. Many simple assays for DNA detection such as isothermal amplification, DNA visualized detection, , and various microfluidic chips , and cartridges integrated with extraction, amplification, and detection have been developed to meet the requirements of POCT. − …”

Dual Gold Nanoparticle/Chemiluminescent Immunoassay for Sensitive Detection of Multiple Analytes

“…Thus, the simultaneous detection of antibiotics and mycotoxins is of significance. To detect antibiotic residues or mycotoxins in foods, researchers developed various methods including gas chromatography-mass spectrometry, liquid chromatography, liquid chromatography-mass spectrometry, and enzyme-linked immunoassay. − Although these methods have high sensitivity and good stability, most of them are complicated and time-consuming and rely on expensive equipment, which requires complex pretreatment of samples before analysis, and are limited to well-equipped laboratories . Furthermore, these methods are not suitable for the immediate detection of multiple samples.…”

Liposome-Embedded Cu2–xAgxS Nanoparticle-Mediated Photothermal Immunoassay for Daily Monitoring of cTnI Protein Using a Portable Thermal Imager

“…At the molecular level, the construction of efficient photothermal biosensors has driven the integration and development in the field of materials science and target analysis. Fu et al developed a series of nanoparticle-mediated photothermal immunoassays, the most notable of which pioneered association of photothermal materials with bioassays. − Inspired by this, we have proposed a temperature biosensor based on the Seebeck effect for the sensitive determination of α-fetoprotein (AFP) . In short, developments in photothermal immunosensing devices have opened up new paths for low-cost biomarker detection, particularly in daily disease surveillance.…”