The investigation of chlorpyrifos (Cpy) detection of PEDOT:PSS-MXene(Ti2CTX)-BSA-GO composite using P-ISFET reduction method

MXenes are two-dimensional materials that are attractive for applications as sensors because they possess high conductivity, super hydrophilicity and high surface area. There already exist substantial researches on the use of Ti3C2Tx based MXenes as electrochemical biosensors, but in contrast Ti2CTX based MXenes are rarely discussed due to their inherent resistance instability. However, the use of Ti2CTX based MXenes is still worth exploring as theoretical studies have shown that Ti2CTX possesses a significantly lower bandgap compared to many other MXenes structures. Herein, this study examines the use of Ti2CTX MXene structures in a P-channel ion-sensitive field-effect transistor (P-ISFET) for the detection of Chlorpyrifos (Cpy). Compositing the PEDOT:PSS thin film with delaminated Ti2CTX MXenes flakes with graphene oxide (GO) and bovine serum albumin (BSA) allows it to maintain its sheet resistance at around 100 kOhm for 3 days. Interestingly when using the composite thin film, the minimum threshold voltage required to observe Cpy electroreduction is −0.1 V. This is much lower than that when using titanium dioxide (TiO2), which is −1.5 V. Composite thin films containing Ti2CTX MXene are found to detect Cpy with higher sensitivity compared to thin films without MXene. This is because the presence of Mxene in the PEDOT:PSS composite thin films improves the surface area available for Cpy detection. This study highlights the potential of Ti2CTx MXene-BSA composite as a promising 2D material for enzyme-free CPY detection

Synthesis of (cinnamate-zinc layered hydroxide) intercalation compound for sunscreen application

Background: Zinc layered hydroxide (ZLH) intercalated with cinnamate, an anionic form of cinnamic acid (CA), an efficient UVA and UVB absorber, have been synthesized by direct method using zinc oxide (ZnO) and cinnamic acid as the precursor. Results: The resulting obtained intercalation compound, ZCA, showed a basal spacing of 23.9 Å as a result of cinnamate intercalated in a bilayer arrangement between the interlayer spaces of ZLH with estimated percentage loading of cinnamate of about 40.4 % w/w. The UV–vis absorption spectrum of the intercalation compound showed excellent UVA and UVB absorption ability. Retention of cinnamate in ZLH interlayers was tested against media usually came across with sunscreen usage to show low release over an extended period of time. MTT assay of the intercalation compound on human dermal fibroblast (HDF) cells showed cytotoxicity of ZCA to be concentration dependent and is overall less toxic than its precursor, ZnO. Conclusions: (Cinnamate-zinc layered hydroxide) intercalation compound is suitable to be used as a safe and effective sunscreen with long UV protection effect

Development of auditing in Malaysia: Legal, political and historical influences

This work investigates the role and contribution of external auditing as practised in the Malaysian society during the forty year period from independence in 1957 to just before the onset of the Asian Financial Crisis in 1997.It applies the political economic theory introduced by Tinker (1980) and refined by Cooper & Sherer (1984), which focuses on the social relations aspects of professional activity rather than economic forces alone.In a case study format where qualitative data was gathered mainly from primary and secondary source materials, the study found that the function of auditing in the Malaysian society in most cases is devoid of any essence of mission; instead it is created, shaped and transformed by the pressures which give rise to its development over time.The largely insignificant role that it serves is intertwined within the contexts in which it operates

Retracted: Smart cane with human detection capabilities for blind people

This article was withdrawn and retracted by the Journal of Fundamental and Applied Sciences and has been removed from AJOL at the request of the journal Editor in Chief and the organisers of the conference at which the articles were presented (www.iccmit.net). Please address any queries to [email protected]