Effective testing tools for Escherichia coli O157:H7 can prevent outbreaks of foodborne illness. In this paper, a smartphone-based colorimetric aptasensor was developed using functionalized gold nanoparticles (GNP) and multi-walled carbon nanotubes (MWCNT) monitoring E. in milk. The maximum absorption peak GNP bonded with aptamer (Apt) generated evident transformation from 518 to 524 nm. excess...

A novel aptamer and surface plasmon resonance (SPR)-based sensor was developed for the label-free detection of lysozyme. The aptasensor is characterised by a detection limit of 1 μg mL(-1) and a linear range of 5-50 μg mL(-1). As an application, we examined the usefulness of the aptasensor for monitoring the early stages of the aggregation of lysozyme. It was surprisingly found that, despite a ...

The aim of this research was to develop a simple, selective and sensitive aptasensor for detection of Pb2+ based on hairpin structure of complementary strand (CS) of aptamer (Apt). Screen printed carbon electrode (SPCE) was electrodeposited by gold nanoparticles to be used as the substrate for the immobilization of Apt-CS. Moreover, gold nanoparticles (AuNPs) and thionine were added to increase...

Aflatoxins are a group of fungal mycotoxins produced mainly by molds, e.g. Aspergillus flavus and Aspergillus parasiticus. Among Aflatoxins, Aflatoxin B1 (AFB1) is the most toxic. Therefore, there is a prompt need for determination of AFB1 in food products. This paper reports an electrochemical aptasensor for accurate determination of AFB1, which was constructed by the using gold nanorod sensin...

An impedimetric aptasensor for ochratoxin A (OTA) detection has been developed on the base of a gold electrode covered with a new modifier consisting of electropolymerized Neutral Red and a mixture of Au nanoparticles suspended in the dendrimeric polymer Botlorn H30®. Thiolated aptamer specific to OTA was covalently attached to Au nanoparticles via Au-S bonding. The interaction of the aptamer w...

An electrochemical aptasensor was developed for the detection of tetracycline using ssDNA aptamer that selectively binds to tetracycline as recognition element. The aptamer was highly selective for tetracycline which distinguishes minor structural changes on other tetracycline derivatives. The biotinylated ssDNA aptamer was immobilized on a streptavidin-modified screen-printed gold electrode, a...

We report a new polydiacetylene (PDA) sensor strip for simple visual detection of zinc ions in aqueous solution. The specificity of this sensor comes from Zn2+ DNA aptamer probes conjugated onto PDA. Effects of aptamer length and structure on the sensitivity of PDA's color transition were first investigated. PDA conjugated with the optimal aptamer sequence was then coated onto a strip of polyvi...

An aptasensor with enhanced anti-fouling properties has been developed. As a case study, the aptasensor was designed with specificity for human thrombin. The sensing platform was developed on screen printed electrodes and is composed of a self-assembled monolayer made from a ternary mixture of 15-base thiolated DNA aptamers specific for human thrombin co-immobilised with 1,6-hexanedithiol (HDT)...

A selective aptasensor was developed using the electrochemical transduction method for the ultrasensitive detection of cocaine. In this method, dendrimer-quantum dot (Den-QD) bioconjugate was utilized as a specific nanocomposite to efficiently fabricate the aptasensor. CdTe QD, which carries highly significant properties, was immobilized on the surface of a glassy carbon electrode (GCE), and po...