Addressable Label-Free Photoelectric Sensor Array with Self-Calibration for Detection of Neuron Specific Enolase.

An addressable label-free photoelectric immunosensor array was designed for detection of neuron specific enolase (NSE) based on TiO/CdS as substrate materials. In this work, the hydrothermal synthesized TiO nanorod film is evenly grown on the surface of the fluorine-doped tin oxide (FTO), and then CdS with a narrow band gap is added for sensitization through successive ionic layer adsorption reactions. The obtained TiO/CdS composite materials with matched energy band structures promote the rapid electron transfer and effectively reduce the recombination of electron hole pairs, which greatly enhance the visible light absorption and increased photocurrent intensity.

Enzyme-Free Colorimetric Immunoassay for Protein Biomarker Enabled by Loading and Disassembly Behaviors of Polydopamine Nanoparticles.

In this work, a mussel-inspired polydopamine (PDA) nanoparticle with biocompatible and reactive surface characteristics was desirably incorporated with high loading capacity and pH-induced disassembly-releasing behavior toward Fe(III) ions to develop an enzyme-free colorimetric immunoassay. The catechol functional network of PDA can act as a scaffold to coordinate with large amounts of Fe(III) ions to form the PDA-Fe(III) NPs whose coordination state can be tailored by changing the pH values. In detail, PDA-Fe(III) NPs can be maintained in a disassembled tri-coordinate state under alkaline conditions while the highly loaded Fe(III) ions can be easily released under acid conditions to react with ferrocyanide for the in situ generation of Prussian blue (PB) NPs.

Ultrasensitive immunosensor for prostate specific antigen using biomimetic polydopamine nanospheres as an electrochemiluminescence superquencher and antibody carriers.

In this work, biomimetic polydopamine nanospheres (PDANSs) were easily prepared and were firstly exploited as an electrochemiluminescence (ECL) nanoquencher for the development of a sandwich type immunosensor. The PDANSs with abundant active functional groups can facilely label the detection antibody and show remarkable quenching effect towards the ECL of the tris-(2,2'-bipyridine)ruthenium (Ru(bpy)). The amino-modified multiwall carbon nanotubes/Nafion (MWCNTs-NH@N) composite-film was adopted as a matrix to incorporate the luminophor Ru(bpy) and immobilize the capture antibody.