Layered Aggregation with Steric Effect: Morphology‐Homogeneous Semiconductor MoS₂ as an Alternative 2D Probe for Visual Immunoassay

Abstract

Liquid-phase exfoliation routes unavoidably generate 2D nanostructures with inhomogeneous morphologies. Herein, thickness-dependent sorting of exfoliated nanostructures is achieved via a treatment of differential-zone centrifugation in the surfactant aqueous phase. With this approach, homogeneous MoS nanosheets are obtained, and due to the intrinsic semiconducting characteristics, those 2D nanosheets are endowed with desired optical properties, rivaling classic gold nanoparticles in sensing applications. Furthermore, MoS nanosheets with high uniformity and chemical inertness are coupled with proteins, exhibiting high performance in stability and anti-interferences for bioanalysis. As a consequence of aggregation-induced steric effect, distinguishing running shifts of antibody-anchored conjugates in gel electrophoresis are visually responsive to those specific antigens. This assay enables the easy and fast monitoring of tumor biomarkers just according to "naked-eye" identification of band location in electrophoresis results, which are presented by an alternative visual probe of 2D MoS -protein conjugates. The developed visual immunoassay with the synergistic effect of gel electrophoresis techniques and 2D semiconductors pushes significant progress in "home-made" tests for disease early diagnosis.

Functionalized MoS2-Based Nanomaterials for Cancer Phototherapy and Other Biomedical Applications

“…MoS 2 NSs and QDs are usually prepared by top-down and bottom-up approaches. The former methods use chemical or physical forces to exfoliate MoS 2 NSs with single or few layers from bulk MoS 2 through cleaving the weak van der Waals’ force between MoS 2 NSs, including various exfoliation techniques such as solvent-assisted exfoliation, liquid exfoliation, , mechanical exfoliation, chemical exfoliation, and electrochemical exfoliation. While the latter methods use precursors containing molybdenum and sulfur elements to react under specific conditions, including chemical vapor deposition, hydrothermal deposition and solvothermal method.…”

“…The most representative of 2D TMDs, with the unique planar structures and superb electronic and optical properties such as thickness-dependent bandgap, strong near-infrared absorbance, large surface area, easily functionalized surface sites, etc., become promising nanoplatforms for various applications in biomedicine, such as drug delivery, phototherapy, biosensing, bioimaging, theranostics, and antimicrobials. 54,65 mechanical exfoliation, chemical exfoliation, 66 and electrochemical exfoliation. While the latter methods use precursors containing molybdenum and sulfur elements to react under specific conditions, including chemical vapor deposition, hydrothermal deposition 67 and solvothermal method.…”

Rapid preparation of polydopamine coating as a multifunctional hair dye

“…4 However, organic compounds with molecular masses of less than 500 Da, such as PPD, have been shown to easily cross the skin barrier and are regarded as human allergens and carcinogens. 5 To address this issue, some nontoxic nanomaterials, which are versatile in biomedical, [6][7][8] nano-engineering, 9,10 and clean energy 11,12 applications, have also been developed as safe dyeing agents. For example, Huang and coworkers found that graphene-based hair dyes could greatly shorten the dyeing time and improve antistatic performance.…”

Toxicity of Two-Dimensional Layered Materials and Their Heterostructures

“…29 BSA could be attached on exfoliated MoS 2 with enhanced stability and performance. 28,71 Effect of nanoparticles interaction on viability of 4T1 cells was measured after treatment of different concentrations of MoS 2 @BSA for 24 or 48 h by CCK-8 assay (Figure 4). The BSA-modified MoS 2 exhibited limited toxicity.…”