Determination of Morphine in Human Urine by the Novel Competitive Fluorescence Immunoassay

Electrochemical measurement of morphine using a sensor fabricated from the CuS/g-C3N5/Ag nanocomposite

Morphine, as one of the most important narcotic drugs, significantly affects the nervous system and increases euphoria, which raises the likelihood of its misuse. Therefore, its measurement is of great importance. In this work, a new electrochemical sensor based on a nanocomposite of CuS/g-C3N5/AgNPs was developed for modifying Screen printed carbon electrodes (SPCEs) and used for the measurement of morphine through cyclic voltammetry and differential pulse voltammetry. Various analytical methods initially characterized the nanocomposite. The prepared sensor, which also has an extensive surface area, achieved a detection limit of 0.01 µM for morphine in a concentration range of 0.05-100 µM at pH 7. Besides its excellent capability in measuring morphine in real samples, the sensor exhibits good stability, reproducibility, and repeatability. The presence of CuS, due to its excellent high surface area alongside silver nanoparticles, leads to an increase in the conductivity of the g-C3N5 modified electrode, resulting in an increased oxidative current of morphine at the surface of the prepared sensor. Therefore, measuring low concentrations of morphine with this sensor was made possible. Additionally, measuring morphine without interference from various species is a strong point of the electrochemical sensor for morphine detection, and combined with the simplicity and ease of the method, it allows for morphine measurements to be conducted in the shortest possible time.

Europium Nanoparticles-Based Fluorescence Immunochromatographic Detection of Three Abused Drugs in Hair

Drug abuse is becoming increasingly dangerous nowadays. Morphine (MOP), methamphetamine (MET) and ketamine (KET) are the most commonly abused drugs. The abuse of these drugs without supervision can cause serious harm to the human body and also endanger public safety. Developing a rapid and accurate method to screen drug suspects and thus control these drugs is essential to public safety. This paper presents a method for the simultaneous quantitative detection of these three drugs in hair by a europium nanoparticles-based fluorescence immunochromatographic assay (EuNPs-FIA). In our study, the test area of the nitrocellulose membrane was composed of three equally spaced detection lines and a quality control line. The test strip realized the quantitative analysis of the samples by detecting the fluorescence brightness of the europium nanoparticles captured on the test line within 15 min. For the triple test strip, the limits of detection of MOP, KET and MET were 0.219, 0.079 and 0.329 ng/mL, respectively. At the same time, it also showed strong specificity. The strip was stable and could be stored at room temperature for up to one year, and the average recovery rate was 85.98-115.92%. In addition, the EuNPs-FIA was validated by high-performance liquid chromatography (HPLC) analysis, and a satisfactory consistency was obtained. Compared to the current immunochromatographic methods used for detecting abused drugs in hair, this method not only increased the number of detection targets, but also ensured sensitivity, improving detection efficiency to a certain extent. The approach can also be used as an alternative to chromatography. It provides a rapid and accurate screening method for the detection of abused drugs in hair and has great application prospects in regard to public safety.

Emerging trends in point-of-care sensors for illicit drugs analysis

Consumption of illicit narcotic drugs and fatal or criminal activities under their influence has become an utmost concern worldwide. These drugs influence an individual's feelings, perceptions, and emotions by altering the state of consciousness and thus can result in serious safety breaches at critical workplaces. Point-of-care drug-testing devices have become the need-of-the-hour for many sections such as the law enforcement agencies, the workplaces, etc. for safety and security. This review focuses on the recent progress on various electrochemical and optical nanosensors developed for the analysis of the most common illicit drugs (or their metabolites) such as tetrahydrocannabinol (THC), cocaine (COC), opioids (OPs), amphetamines & methamphetamine, and benzodiazepine (BZDs). The paper also highlights the sensitivity and selectivity of various sensing modalities along with evolving parameters such as real-time monitoring and measurement via a smart user interface. An overall outlook of recent technological advances in point of care (POC) devices and guided insights and directions for future research is presented.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Monoclonal Antibodies Application in Lateral Flow Immunochromatographic Assays for Drugs of Abuse Detection

Lateral flow assays (lateral flow immunoassays and nucleic acid lateral flow assays) have experienced a great boom in a wide variety of early diagnostic and screening applications. As opposed to conventional examinations (High Performance Liquid Chromatography, Polymerase Chain Reaction, Gas chromatography-Mass Spectrometry, etc.), they obtain the results of a sample's analysis within a short period. In resource-limited areas, these tests must be simple, reliable, and inexpensive. In this review, we outline the production process of antibodies against drugs of abuse (such as heroin, amphetamine, benzodiazepines, cannabis, etc.), used in lateral flow immunoassays as revelation or detection molecules, with a focus on the components, the principles, the formats, and the mechanisms of reaction of these assays. Further, we report the monoclonal antibody advantages over the polyclonal ones used against drugs of abuse. The perspective on aptamer use for lateral flow assay development was also discussed as a possible alternative to antibodies in view of improving the limit of detection, sensitivity, and specificity of lateral flow assays.

Determination of morphine and its metabolites in the biological samples: an updated review

Morphine (MO) as an opioid analgesic is used for the treatment of moderate-to-severe pains, particularly cancer-related pains. Pharmacologic studies on MO are complicated due to drugs binding to the protein or metabolization to active metabolites, and even inter-individual variability. This necessitates the selection of a reliable analytical method for monitoring MO and the concentrations of its metabolites in the biological samples for the pharmacokinetic or pharmacodynamic investigations. Therefore, this study was conducted to review all the analytical research carried out on MO and its metabolites in the biological samples during 2007-2019 as an update to the study by Bosch et al. (2007).