BACKGROUND Gold nanoparticles have been widely employed for biosensing purposes with remarkable efficacy for DNA detection. Amongst the proposed systems, colorimetric strategies based on the remarkable optical properties have provided for simple yet effective sequence discrimination with potential for molecular diagnostics at point of need. These systems may also been used for parallel detectio...

The development of new sensitive, cost-effective and user-friendly colorimetric bioassays is in increasing demand to meet the requirement of modern clinical diagnostics and field detection. Herein, a novel iron oxide-to-Prussian blue (PB) nanoparticle (NP) conversion strategy was developed and applied to sensitive colorimetric immunosensing of cancer biomarkers. In a typical sandwich-type immun...

Rapid and sensitive detection methods are in urgent demand for the screening of extensively used organophosphorus pesticides and highly toxic nerve agents for their neurotoxicity. In this study, we developed a novel Fe(3)O(4) magnetic nanoparticle (MNP) peroxidase mimetic-based colorimetric method for the rapid detection of organophosphorus pesticides and nerve agents. The detection assay is co...

The development of a green and facile strategy for synthesizing high stable gold nanoparticles (AuNPs) is still highly challenging. Additionally, the main problems regarding AuNPs based colorimetric sensors are their poor selectivity and low sensitivity, as well their tendency to aggregate during their synthesis and sensing process. Herein, we present an in-situ reduction strategy to synthesize...

MicroRNAs are small regulatory molecules that can be used as potential biomarkers of clinical diagnosis, and efforts have been directed towards the development of a simple, rapid, and sequence-selective analysis of microRNAs. Here, we report a simple and versatile colorimetric strategy for ultrasensitive and specific determination of microRNAs based on molecular beacon initiated strand displace...

Circular DNA is used as a template for the amplified detection of M13 phage ssDNA by a rolling circle amplification (RCA) process that synthesizes DNAzyme chains, thus enabling the colorimetric or chemiluminescent detection of the analyte.

We have developed a highly sensitive and selective colorimetric method for detection of acetylcholine (ACh), using a tandem enzymatic reaction for biological target recognition and silver nanoplates (AgNPLs) for optical signal generation. The ACh molecules are enzymatically hydrolyzed and oxidized into betaine and hydrogen peroxide, the latter of which chemically oxidizes the AgNPLs to generate...

Biopharmaceutical products must be proved to be minimized as much as possible of contaminating host cell proteins (HCPs) prior to approval by the regulatory authorities. Commonly, ELISAs are used for HCP determination and authorities ask for clear and manifest proof that the antibodies used in the HCP ELISA are fit for purpose. Their suitability needs to be shown, not only by the obtained ELISA...