Nuclear chemistry

Quantum mechanics

Alkaline phosphatase

Nanoparticle

Biology

Materials science

Chromatography

Biochemistry

In situ

Silicon

LNCaP

Substrate (aquarium)

Immunoassay

Geology

Colorimetry

Oceanography

Immunology

Ethylenediamine

Combinatorial chemistry

Physics

Nanotechnology

Organic chemistry

Chromogenic

Enzyme

Fluorescence

Internal medicine

Medicine

Chemistry

Antibody

Cancer

Cancer cell

Analytical Chemistry

Enzyme-triggered in situ chromogenic and/or fluorogenic reactions under accessible conditions are significant for developing enzyme activity and related spectroscopic assays. Here, we describe a facile one-pot synthetic strategy to prepare silicon-containing nanoparticles with yellow-green fluorescence and orange-red color by mixing N-[3-(trimethoxysilyl)propyl]ethylenediamine and p-aminophenol (AP) in aqueous solution at a mild temperature. Encouraged by the AP-regulated simple synthetic procedure and the generation of AP from alkaline phosphatase (ALP)-catalyzed hydrolysis of 4-aminophenol phosphate (APP), a fluorometric and colorimetric dual-readout ALP activity assay can be rationally envisioned and developed by employing APP as the substrate. In the wake of the good analytical performance of such ALP activity assay and its successful combination with enzyme-linked immunosorbent assay (ELISA), corresponding fluorometric and colorimetric dual-readout ALP-based ELISA has been constructed for highly sensitive and quantitative determination of human prostate-specific antigen (PSA), the key biomarker of prostate cancer in human serum. The convincing performance in evaluating the PSA level in serologic tests unambiguously reveals the great potential of our proposed fluorometric and colorimetric dual-channel immunoassay in early clinical diagnosis by monitoring disease biomarkers.

Alkaline Phosphatase-Triggered in Situ Formation of Silicon-Containing Nanoparticles for a Fluorometric and Colorimetric Dual-Channel Immunoassay