A preliminary investigation into the use of biosensors to screen stomach contents for selected poisons and drugs

A Convenient Electrochemiluminescent Immunosensor for Detecting Methamphetamine Antibody

An antibody-based immunotherapy for methamphetamine (MA) addictive treatment is has been drawing more and more attention in recent years. However, studies about methamphetamine antibody (anti-MA) immunodetections are rare, owing to the lack of immunogenicity of small molecule MA. This study provides a simple and effective approach to develop a convenient electrochemiluminescent (ECL) immunosensor for the testing of anti-MA. In short, the synthetic holoantigen of MA is immobilized on a homemade gold nanoparticles modified electrode as the sensing host for the specific recognition and detection of anti-MA. The research suggested, under optimal experimental conditions, the ECL intensity on resultant immunosensor has a wide-linear regression toward the anti-MA quantity within the range from 0.03 to 3.07 ng with a detection limit of 2.32 pg. It responded to the dosage of anti-MA in spiked blood samples with satisfactory recovery. According to the research, the developed sensor shows promise as a portable Anti-MA fast seized device which performs quickly and offers convenience, and will be helpful for forensic identification and clinical treatment.

A review on amperometric-type immunosensors based on screen-printed electrodes

In this brief review, we summarize the recent research activities involved in the development of amperometric-type immunosensors based on screen-printed electrodes (SPEs). We focus on the underlying principle involved in these types of sensors, their fabrication and electrode surface modification. We also discuss the various factors involved in the designing of such immunosensors and how they affect their performances. Finally we provide an insight into the drawbacks associated with these SPEs.

Biosensor based on atemoya peroxidase immobilised on modified nanoclay for glyphosate biomonitoring

A biosensor based on atemoya peroxidase immobilised on modified nanoclay was developed for the determination of glyphosate by the enzyme inhibition method. The inhibitor effect of the biocide results in a decrease in the current response of the hydroquinone that was used as a phenolic substrate to obtain the base signal. The biosensor was constructed using graphite powder, multiwalled carbon nanotubes, peroxidase immobilised on nanoclay and mineral oil. Square-wave voltammetry was utilised for the optimisation and application of the biosensor, and several parameters were investigated to determine the optimum experimental conditions. The best performance was obtained using a 0.1 mol L(-1) phosphate buffer solution (pH 7.0), 1.9×10(-4) mol L(-1) hydrogen peroxide, a frequency of 30 Hz, a pulse amplitude of 50 mV and a scan increment of 4 mV. The glyphosate concentration response was linear between 0.10 and 4.55 mg L(-1) with a detection limit of 30 μg L(-1). The average recovery of glyphosate from spiked water samples ranged from 94.9 to 108.9%. The biosensor remained stable for a period of eight weeks.

A unifying review of bioassay-guided fractionation, effect-directed analysis and related techniques

The success of modern methods in analytical chemistry sometimes obscures the problem that the ever increasing amount of analytical data does not necessarily give more insight of practical relevance. As alternative approaches, toxicity- and bioactivity-based assays can deliver valuable information about biological effects of complex materials in humans, other species or even ecosystems. However, the observed effects often cannot be clearly assigned to specific chemical compounds. In these cases, the establishment of an unambiguous cause-effect relationship is not possible. Effect-directed analysis tries to interconnect instrumental analytical techniques with a biological/biochemical entity, which identifies or isolates substances of biological relevance. Successful application has been demonstrated in many fields, either as proof-of-principle studies or even for complex samples. This review discusses the different approaches, advantages and limitations and finally shows some practical examples. The broad emergence of effect-directed analytical concepts might lead to a true paradigm shift in analytical chemistry, away from ever growing lists of chemical compounds. The connection of biological effects with the identification and quantification of molecular entities leads to relevant answers to many real life questions.

Mobility and survival of Salmonella Typhimurium and human adenovirus from spiked sewage sludge applied to soil columns

AIMS

This study investigated the survival and transport of sewage sludge-borne pathogenic organisms in soils.

METHODS AND RESULTS

Undisturbed soil cores were treated with Salmonella enterica ssp. enterica serovar Typhimurium-lux (STM-lux) and human adenovirus (HAdV)-spiked sewage sludge. Following an artificial rainfall event, these pathogens were analysed in the leachate and soil sampled from different depths (0-5 cm, 5-10 cm and 10-20 cm) after 24 h, 1 and 2 months. Significantly more STM-lux and HAdV leached through the soil cores when sewage sludge was present. Significantly more STM-lux were found at all soil depths, at all time periods in the sewage sludge treatments, compared to the controls. The rate of decline of STM-lux in the controls was more rapid than in the sewage sludge treatments. Survival and transport of HAdV were minimal.

CONCLUSIONS

The presence of sewage sludge can significantly influence the transport and survival of bacterial pathogens in soils, probably because of the presence of organic matter. Environmental contamination by virus is unlikely because of strong soil adsorption.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study suggests that groundwater contamination from vertical movement of pathogens is a potential risk and that it highlights the importance of the treatment requirements for biosolids prior to their application to land.