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Food security is critical for the sustainability of society. The spoilage of stocked food is an ongoing problem that causes significant losses to the global economy. Novel portable analytical platforms that provide timely information on the condition of food stock can support informed decision‐making on the safety of food consumption as well as on maximization of food storage lifetime. Ammonia (NH3) and hydrogen sulfide (H2S) are two of the major harmful gases that are produced due to bacteria activity during the food spoilage process. The timely detection of these gases in food stocks has vital importance to human health. In this review article, the recent progress of conducting polymer based NH3 and H2S gas sensors including sensor device prototypes, their sensing mechanisms, materials and methodologies for sensor fabrication, and their suitability for the development of consumer electronic devices for food spoilage detection are highlighted. [ABSTRACT FROM AUTHOR]

The versatile nature of organic conjugated materials renders their flawless integration into a diverse family of optoelectronic devices with light‐harvesting, photodetection, or light‐emitting capabilities. Classes of materials that offer the possibilities of two or more distinct optoelectronic functions are particularly attractive as they enable smart applications while providing the benefits of the ease of fabrication using low‐cost processes. Here, we develop a novel, multi‐purpose conjugated small molecule by combining boron‐azadipyrromethene (aza‐BODIPY) as electron acceptor with triphenylamine (TPA) as end‐capping donor units. The implemented donor–acceptor–donor (D–A–D) configuration, in the form of TPA‐azaBODIPY‐TPA, preserves ideal charge transfer characteristics with appropriate excitation energy levels, with the additional ability to be used as either a charge transporting interlayer or light‐sensing semiconducting layer in optoelectronic devices. To demonstrate its versatility, we first show that TPA‐azaBODIPY‐TPA can act as an excellent hole transport layer in methylammonium lead triiodide (MAPbI3)‐based perovskite solar cells with measured power conversion efficiencies exceeding 17%, outperforming control solar cells with PEDOT:PSS by nearly 60%. Furthermore, the optical bandgap of 1.49 eV is shown to provide significant photodetection in the wavelength range of up to 800 nm where TPA‐azaBODIPY‐TPA functions as donor in near‐infrared organic photodetectors (OPDs) composed of fullerene derivatives. Overall, the established versatility of TPA‐azaBODIPY‐TPA, combined with its robust thermal stability as well as excellent solubility and processability, provides a new guide for developing highly efficient multi‐purpose electronic materials for the next‐generation of smart optoelectronic devices. [ABSTRACT FROM AUTHOR]

Cyanide (CN−) is one of the most hazardous ions to humans and the environment. Therefore, sensitive, and selective sensors for CN− monitoring are highly required. A novel chemosensor based on naphthalene flanked diketopyrrolopyrrole dye (TBC‐DPPN) is synthesized for the direct detection of CN− in water samples by naked eye and vibrational spectroscopy (UV–Vis and fluorescence). The electron deficient carbonyl group of the lactam ring of TBC‐DPPN undergoes a nucleophilic attack by the CN− thus causing the yellow color of the dye turn to colorless, and fluorescence of the dye at 527 nm to turn‐off. The mechanism of CN− sensing by the TBC‐DPPN sensor is confirmed by spectral measurements and density functional theory (DFT) calculations. The TBC‐DPPN sensor is utilized to determine the CN− by colorimetric and fluorescence methods in water down to 0.5 and 0.05 µm, respectively, which is well below the cut off limit of 1.9 µm that is recommended by the World Health Organization (WHO). Therefore, TBC‐DPPN can act as dual channel sensor with high selectivity and sensitivity for the determination of CN− in water. [ABSTRACT FROM AUTHOR]

In this work, we utilise the disulphide bond structure of insulin and a new benzothiazole Raman probe for the detection of human insulin using surface‐enhanced Raman spectroscopy (SERS). The disulphide bond structure of the insulin was reduced to generate free sulfhydryl terminal groups. When reacted with benzothiazole‐functionalised gold nanoparticles, the reduced protein desorbs the Raman probe and causes its Raman signal intensity to quench. Using this approach, insulin was quantified in the concentration range of 1 × 10−14–1 × 10−8 M by SERS quenching. The limit of quantification of insulin by the SERS quenching method was found to be 1 × 10−14 M (0.01 pM or 58 pg/L), which satisfies the requirements for monitoring its blood concentration in patients. Because many proteins and peptides have disulphide bonds in their molecular structures, the new SERS quenching method has a strong potential for the rapid determination of ultralow concentrations of proteins in formulations and biological fluids. [ABSTRACT FROM AUTHOR]

Recombinant human erythropoietin (rHuEPO) is an important hormone drug that is used to treat several medical conditions. It is also frequently abused by athletes as a performance enhancing agent at sporting events. The time window of the rHuEPO in blood is short. Therefore, the rapid detection of rHuEPO use/abuse at points of care and in sports requires a selective analytical method and a sensitive sensor. Herein, we present a highly selective method for the rapid detection of rHuEPO in human blood plasma by a sensitive optical sensor. rHuEPO is selectively extracted from human blood plasma by a target-specific extractor chip and converted into a biothiol by reducing its disulfide bond structure. The formed biothiol reacts with a water soluble (E)-1-((6-methoxybenzo[d]thiazole-2-yl)diazenyl)naphthalene-2,6-diolHg(II) (BAN-Hg) optical sensor and causes its rapid decomposition. This leads to a rapid change in the sensor color from blue to pink that can be observed by the naked eye. The optical sensor was used to quantify rHuEPO in the concentration range 1 × 10−8 M to 1 × 10−12 M by UV–Vis spectroscopy. For the screening of blood plasma, an EPO-specific extractor chip was synthesized and used to selectively extract the protein from the biological matrix prior to its conversion into biothiol and quantification by the optical sensor. Since many proteins have a disulfide bond structure, the new method has strong potential for their rapid sensitive and selective detection by the BAN-Hg sensor and UV–Vis spectroscopy. [ABSTRACT FROM AUTHOR]

A new benzothiazole azo dye [(E)-1-((6-methoxybenzo[d]thiazole-2-yl)diazenyl)naphthalene-2,6-diol] (also known as “BAN”), has been synthesised and used as a chemosensor for the rapid and selective detection of mercury(ii) ions in water. The pink coloured chemosensor turns blue when reacted with mercury(ii) ions due to the formation of a 2 : 1 coordination complex. The complex formation causes a bathochromic shift of the chemosensor's UV absorption peak from 540 to 585 nm and turns on a highly selective fluorescence emission at 425 nm. The change in the optical property of BAN upon complexation with mercury(ii) was confirmed by ab initio calculations. The new chemosensor was used to quantify mercury(ii) ions in water by fluorescence spectroscopy down to 5 × 10−8 M (10 ppb). The limit of detection (LOD) of Hg2+ was 9.45 nM (1.8 ppb) which satisfies the maximum allowable Hg2+ concentration in drinking water that is set by the WHO. The BAN–Hg(ii) complex was used for the determination of cysteine (Cys) in aqueous solution by UV-Vis spectroscopy down to 1 × 10−7 M. The thiol-containing amino acid preferentially coordinates the mercury ions of the BAN–Hg(ii) complex. This causes dissociation of the blue-coloured complex and the liberation of the pink-coloured BAN dye. The colour change of the BAN–Hg(ii) complex from blue to pink was selective to the Cys biothiol while other non-thiol containing amino acids did not cause a colour change. For the in-field application, filter paper strips were loaded with the BAN–Hg(ii) complex and used as a disposable sensor for the detection of cysteine (Cys) by the naked eye. Therefore, the BAN chemosensor offers a sensitive, and rapid tool for the detection of mercury(ii) in water. In addition, the BAN–Hg(ii) complex can be used as a simple and selective chemosensor of the screening of purified biothiols, such cysetine, homocysteine and glutathione in biology research and pharmaceutical/food industries. [ABSTRACT FROM AUTHOR]

This cover (DOI: 10.1002/inf2.12345) shows a multifunctional TPA‐azaBODIPY‐TPA small molecule with superior optoelectronic and photophysical properties. Material is shown to function as an efficient hole transport layer in perovskite solar cells reaching a power conversion efficiency of 17.4%, and as a robust electron donor in near‐infrared organic photodetectors absorbing light in the wavelength range of up to 800 nm. Offering two distinct optoelectronic functions, TPA‐azaBODIPY‐TPA is particularly attractive as it enables multi‐purpose applications while maintaining the ease of fabrication. [ABSTRACT FROM AUTHOR]

A simple colorimetric method for the determination of vaporous aliphatic amines has been developed. Importantly, the recognition of vaporous aliphatic amines could be observed by naked eyes owing to color change of the synthesized azobenzothiazole-polyene dye from orange to dark blue in the solution. The results revealed that primary amines can form 1:2 and secondary amines 1:1 complexes with the dye, respectively. The sensing of this chemosensor is capable over a dynamic linear ranges between 10^\mathrm -2 – 10^\mathrm -6\textM for primary aliphatic amines and 10^\mathrm -2 – 10^\mathrm \mathbf -4\textM for secondary aliphatic amines. The response of the dye to tertiary amines or aromatic amines was not strong enough to make a strong color change. Validation of the assay method revealed excellent performance characteristics, including high repeatability and highly recognizable color change. [ABSTRACT FROM PUBLISHER]