No abstract

No abstract

We found that the formylbenzenediazonium (FBD)-grafted organic layers can be degraded by treating with an aqueous solution of salt and Tween. An electrochemical immunoassay was carried out on the degraded surface, which allowed highly sensitive detection of antigen mouse IgG.

Cost‐effective gas‐phase synthesized single walled carbon nanotubes (SWCNTs) were first employed for the surface modification of indium tin oxides (ITO) via electrostatic coating of poly‐l‐lysine (PLL). Compared with control substrates of bare ITO and SWCNT‐PLL‐slide glasses, SWCNT‐PLL‐ITO, with high catalytic properties associated with large surface areas, showed significant improvement of electro catalytic activity toward the oxidation of dopamine (DA) and uric acid (UA). The cyclic voltammetric (CV) peak separation of oxidation for both DA and UA was estimated to be ∼ 0.13 V, which renders them capable of simultaneously detecting DA and UA in a mixed solution. The differential pulse voltammetry (DPV) technique was further performed to obtain a linear detection range of DA from 1.0 μM to 100 μM, and a detection limit of 1.0 μM was confirmed in the mixed solution. Furthermore, the practical analytical ability of the method was finally confirmed by selective detection of both DA and UA in human urine samples without any preliminary treatment, implying the feasibility of applying bio‐sensors in a low‐cost manner.

Purpose This paper aims to evaluate the effects of banana (Musa) peel and guava (Psidium guajava) leaves extract as mordants on jute–cotton union fabrics dyed with onion skin extract as a natural dye. Design/methodology/approach The dye was extracted from the outer skin of onions by boiling in water and later concentrated. The bio-mordants were prepared by maceration using methanol and ethanol. The fabrics were pre-mordanted, simultaneously mordanted and post-mordanted with various concentrations according to the weight of the fabric. The dyed and mordanted fabrics were later subjected to measurement of color coordinates, color strength and colorfastness to the washing test. Furthermore, the dyed samples were characterized by Fourier transform infrared, and different chemical bonds were analyzed by X-ray photoelectron spectroscopy analysis. Findings Significant improvement was obtained in colorfastness and color strength values in various instances using banana peel and guava leaves as bio mordants. Post-mordanted with banana peel provided the best results for wash fastness. Better color strength was achieved by fabric post-mordanted with guava leave extracts. Originality/value Sustainable dyeing methods of natural dyes using banana peel and guava leaves as bio mordants were explored on jute–cotton union fabrics. Improvement in colorfastness and color strength for various instances was observed. Thus, this paper provides a promising alternative to metallic salt mordants.