Abstract Komagataella phaffii is an important cell factory for recombinant protein production under methanol induction. Tracking of recombinant protein expression by single K. phaffii cell is a hot topic to identify the variation of expression level in submerge cultivation system. In this study, a platform system harnessing Aspergillus niger pellets for K. phaffii cell immobilization in fabricated glass plate was developed to measure the green fluorescent protein (GFP) expression of single cell using fluorescence microscope. This system was optimized through pellets preparation, K. phaffii cell absorption, inducer comparison, methanol concentration, flow velocity of medium, and obtaining a successful platform to track GFP expression of single K. phaffii cell. This system provided an on-line analytical technology to discover the heterogeneous capability of various K. phaffii cells.

Abstract Apixaban (APX) is a novel anticoagulant drug used in the treatment of ischemic stroke and venous thromboembolism. In this study, two different chromatographic methods were developed for the determination of APX in pharmaceutical products. In the first method, an Agilent C18 column (250 mm × 4.6 mm, 5 μm) was used, and the temperature was kept constant at 30°C. The mobile phase was chosen to be 0.1% trifluoroacetic acid solution and acetonitrile (65:35, v/v), and isocratic elution was applied. The flow rate of the mobile phase was found to be 1.0 mL·min−1 and the injection volume was 20 µL. The detection was carried out at a wavelength of 276 nm using a UV detector. In the second method, ethanol was used as an organic modifier. The only difference between these methods was the organic modifier. All other conditions of the methods were the same. Both chromatographic methods were validated in accordance with ICH guidelines for various parameters such as selectivity, linearity, accuracy, precision, detection and quantification limit, and robustness. The determination coefficients of chromatographic methods were greater than 0.999 in the concentration range of 5–30 mg·mL−1 of APX. Later, these chromatographic methods were applied to tablet formulations. Comparison of the obtained results in terms of mean was made using Student’s (t) test, and comparisons in terms of standard deviations were made using the Fisher (F) test. It was observed that there was no significant difference between these methods. These two methods were then evaluated using AGREE-Analytical greenness metric software. The chromatographic method using ethanol as an organic modifier has been proposed as an excellent eco-friendly and analyst-friendly alternative for the determination of APX in pharmaceutical formulations.

Abstract Currently, sample preparation is the most laborious part of the analytical process, requiring the most time and being susceptible to the most errors. In this context, numerous investigations have focused on the miniaturization of these techniques to reduce work time, costs, and errors. In this regard, microextraction by packed sorbent (MEPS) is a simple, fast, and robust sample preparation technique suitable for easy automation in several analytical systems and is applied to a wide variety of samples. Antibiotics are among the most commonly used drugs; however, their extensive and inappropriate use has garnered significant attention in the environment, human health, and food safety. This brief review is intended to provide an overview of recently reported antibiotic extraction methods based on MEPS, with a special interest in those applied to the analysis of biological, environmental, and food samples. In addition, the sample pretreatment step before extraction by the MEPS device was highlighted, as was the description of the sample-related steps within the MEPS procedure, such as extraction, washing, and elution.

Abstract Chemical warfare agents (CWAs) are chemical substances intended for use in military operations to kill, injure, or incapacitate an enemy. It is very important to detect toxic CWAs at trace levels on site. Compared with traditional CWA analysis instrument methods, chemiresistive gas sensors present advantages of being small, fast, and inexpensive. Chemiresistive gas sensors are still an important research topic with the development of nanofabrication technology and new kinds of sensing materials, including carbon nanotubes, graphene, and black phosphorus (BP). Chemiresistive gas sensors are divided into three categories according to the type of sensitive materials: carbon- and BP-based materials, conductive polymers, and metal oxide semiconductors. A brief analysis was carried out on fabrication strategies using sensitive materials, including hydrogen bonding strategies, nanostructures, morphology, doping effects, composite materials, and other material application methods, and the sensitive materials and detection effects are summarized in this study. This review aims to provide guidance in the development of chemiresistive sensors for the detection of CWAs.

Abstract Ashwagandha (Withania somnifera) is a very popular medicinal herb originated mainly in India and found in the Middle East and parts of Africa. Ashwagandha has gained recognition as the most revered plant in Ayurvedic medicine. Studies indicated that it is used as anxiolytic, anti-inflammatory, antioxidant, adaptogen, memory enhancer, and possess an effect on neurodegenerative diseases. Additionally, it was revealed that the plant exerts antibacterial, antiviral, antitumor, aphrodisiac, and cardiovascular protection activities. Due to the biological and nutritional importance of nutraceuticals, particularly ashwagandha, and as part of the ongoing research of the natural products and its bioactive phytochemicals, this review aims to summarize the recent analytical techniques that have been reported for the determination of different chemical constituents of Withania somnifera quantitatively and qualitatively, and to highlight new challenges.

Abstract Sodium-glucose transporter 2 inhibitor emerges as the latest group of oral hypoglycemic agents, which shows insulin-independent pathology and provides an upper hand to enhance renal glucose elimination. Canagliflozin (CGN) was the number one drug, approved by FDA on 29th March 2013 for the treatment of type 2 diabetes mellitus. By totting up to its glucose-lowering effects, it exhibits beneficial effects on the heart and potentially on the kidneys. The study aims to summarize various analytical techniques, such as chromatography, spectrophotometry, and hyphenated techniques, such as Liquid chromatography with tandem mass spectrometry (LC-MS/MS) and Ultra performance liquid chromatography with tandem mass spectrometer (UPLC-MS) for the analysis of CGN. In the proposed work, we have reviewed various analytical methods reported for the estimation of CGN in biological matrices and Pharmaceuticals from various databases like ScienceDirect, Springer, PubMed, Scopus, Taylor & Francis, and Web of Science for the estimation of CGN. Various analytical methods adapted were high-performance liquid chromatography, UPLC, LC-MS/MS, high-performance thin-layer liquid chromatography, Fourier-transform infrared spectroscopy, spectrofluorimetry, and UV spectrophotometry. This current review presented the determination of CGN using various analytical techniques and biological matrices either in single or in combination with other hypoglycemic agents, as per International Conference on Harmonization guidelines. Further, some future trends that can be integrated were also suggested.

Abstract The aim of this work is to purify and characterise bioactive molecules from various solvent extracts prepared with the leaves of Rhizophora mucronata, a mangrove plant. In vitro assessment of antibacterial activity of n-hexane, diethyl ether, ethanol, and aqueous extracts (AEs) against Bacillus subtilis (0.4 ± 0.1, 1.1 ± 0.3, 0.9 ± 0.1, and 1.2 ± 0.7 mm), Staphylococcus aureus (1.2 ± 0.1, 2.3 ± 0.5, 3.2 ± 1.2, and 4.4 ± 1.7 mm), Klebsiella pneumoniae (0.5 ± 0.3, 1.7 ± 0.4, 3.9 ± 1.4, and 3.9 ± 0.9 mm), and Pseudomonas aeruginosa (0.2 ± 0.1, 2.5 ± 0.6, 3.7 ± 0.5, and 4.2 ± 1.3 mm) has proven to act as potent similar to that of commercial antibiotic. Corresponding to antibacterial activity result, antioxidant activity was also higher for AE (75.97% ± 0.5%) compared to remaining extracts (73.77% ± 2.5%, 69.99% ± 0.4%, and 65.24% ± 1.8%) at a concentration of 500 μg·mL−1. Considering both the activities, AE was selected for separation of bioactive molecule by deploying two purification techniques – column chromatography and preparative thin layer chromatography consecutively. After purification, the sample was injected into mass spectrometer and the presence of N-p-coumaroyltyramine and luteolin with excellent antibacterial and antioxidant properties (13.1 ± 2.2 mm and 80.9% ± 2.3%, respectively) were recognised. Further, in vivo investigations on Catla catla fingerlings infected with P. aeruginosa indicated that partially purified extracts cured the infection and resulted in a 100% survival rate.

Abstract Spectroscopic techniques such as infrared spectroscopy and Raman spectroscopy are used for a long time in the context of the analysis of illicit drugs, and their use is increasing due to the development of more performant portable devices and easy application in the context of harm reduction through drug checking or onsite forensic analysis. Although these instruments are routinely used with a spectral library, the importance of chemometric techniques to extract relevant information and give a full characterisation of samples, especially in the context of adulteration, is increasing. This review gives an overview of the applications described in the context of the analysis of illicit drug products exploiting the advantages of the combination of spectroscopy with chemometrics. Next to an overview of the literature, the review also tries to emphasize the shortcomings of the presented research papers and to give an incentive to what is needed to include chemometrics as a part of the daily routine of drug checking services and mobile forensic applications.

Abstract A simple fluorescent chemosensor, 5-(diethylamino)-2-((2-(pyrazin-2-yl) hydrazono)methyl)phenol, has been synthesized by Schiff-base condensation reaction. The chemosensor exhibited highly selective and sensitive “off-on” fluorescent responses toward Al3+ and Zn2+ but the signal of fluorescence emission varies. The detection limits were found to be 2.33 × 10−7 M for Al3+ and 1.68 × 10−7 M for Zn2+, respectively. The binding mechanisms between chemosensor and Al3+ or Zn2+ ions were supported by Job′s, 1H NMR, Fourier transform infrared spectra, and MS experiments. The sensing behavior was also studied with molecular logic functions of OR, AND, and NOT gates. In addition, the chemosensor was able to detect Al3+ and Zn2+ by producing distinct color changes observed by the naked eye on sensor-coated swabs. Moreover, the chemosensor was successfully applied to effectively detect Al3+ and Zn2+ in actual water and drug samples.

Abstract We constructed a non-enzymatic H2O2 sensor based on cuprous oxide-supported silver-modified reduced graphene oxide nanocomposites. It was found that the sensor exhibited good performances for sensing H2O2 with a detection limit of 0.34 μM and a wide detection range of 1–310 μM. The combination of graphene with silver and cuprous oxide improved the sensor’s sensitivity for detecting H2O2, with good repeatability, selectivity, and stability. The synthesis method of this nanocomposite provides a new idea for the green preparation of graphene-based nanocomposites and a new method for the construction of a new electrochemical sensor platform.