Unveiling Morphine: A Rapid and Selective Fluorescence Sensor for Forensic and Medical Analysis.

Opioid use, particularly morphine, is linked to CNS-related disorders, comorbidities, and premature death. Morphine, a widely abused opioid, poses a significant global health threat and serves as a key metabolite in various opioids. Here, we present a turn-off fluorescent sensor capable of detecting morphine with exceptional sensitivity and speed in various samples. The fluorescent sensor was developed through the dimerization process of 7-methoxy-1-tetralone and subsequent demethylation to produce the final product. Despite morphine possessing inherent fluorophoric properties and emitting light in an approximately similar wavelength as the sensor's fluorescent blue light, the introduction of the target molecule (morphine) in the presence of the sensor caused a reduction in the sensor's fluorescence intensity, which is attributable to the formation of the sensor-morphine complex. By utilizing this fluorescence quenching sensor, the chemo-selective detection of morphine becomes highly feasible, encompassing a linear range from 0.008 to 40 ppm with an impressive limit of detection of 8 ppb. Consequently, this molecular probe demonstrates a successful application in determining trace amounts of morphine within urine, yielding satisfactory analytical results. The study also explores the effect of several variables on the sensor's response and optimizes the detection of morphine in urine using a response surface methodology with a central composite design.

Rapid Detection of Amitriptyline in Dried Blood and Dried Saliva Samples with Surface-Enhanced Raman Spectroscopy.

There is growing demand for rapid, nondestructive detection of trace-level bioactive molecules including medicines, toxins, biomolecules, and single cells, in a variety of disciplines. In recent years, surface-enhanced Raman scattering has been increasingly applied for such purposes, and this area of research is rapidly growing. Of particular interest is the detection of such compounds in dried saliva spots (DSS) and dried blood spots (DBS), often in medical scenarios, such as therapeutic drug monitoring (TDM) and disease diagnosis. Such samples are usually analyzed using hyphenated chromatography techniques, which are costly and time consuming. Here we present for the first time a surface-enhanced Raman spectroscopy protocol for the detection of the common antidepressant amitriptyline (AMT) on DBS and DSS using a test substrate modified with silver nanoparticles. The validated protocol is rapid and non-destructive, with a detection limit of 95 ppb, and linear range between 100 ppb and 1.75 ppm on the SERS substrate, which covers the therapeutic window of AMT in biological fluids.

Graphene-Based Electrochemical Sensors for Psychoactive Drugs.

Sensors developed from nanomaterials are increasingly used in a variety of fields, from simple wearable or medical sensors to be used at home to monitor health, to more complicated sensors being used by border customs or aviation industries. In recent times, nanoparticle-based sensors have begun to revolutionize drug-detection techniques, mainly due to their affordability, ease of use and portability, compared to conventional chromatography techniques. Thin graphene layers provide a significantly high surface to weight ratio compared to other nanomaterials, a characteristic that has led to the design of more sensitive and reliable sensors. The exceptional properties of graphene coupled with its potential to be tuned to target specific molecules have made graphene-based sensors one of the most popular and well-researched sensing materials of the past two decades with applications in environmental monitoring, medical diagnostics, and industries. Here, we present a review of developments in the applications of graphene-based sensors in sensing drugs such as cocaine, morphine, methamphetamine, ketamine, tramadol and so forth in the past decade. We compare graphene sensors with other sensors developed from ultrathin two-dimensional materials, such as transition-metal dichalcogenides, hexagonal boron nitrate, and MXenes, to measure drugs directly and indirectly, in various samples.

State of the Art in Alcohol Sensing with 2D Materials.

Since the discovery of graphene, the star among new materials, there has been a surge of attention focused on the monatomic and monomolecular sheets which can be obtained by exfoliation of layered compounds. Such materials are known as two-dimensional (2D) materials and offer enormous versatility and potential. The ultimate single atom, or molecule, thickness of the 2D materials sheets provides the highest surface to weight ratio of all the nanomaterials, which opens the door to the design of more sensitive and reliable chemical sensors. The variety of properties and the possibility of tuning the chemical and surface properties of the 2D materials increase their potential as selective sensors, targeting chemical species that were previously difficult to detect. The planar structure and the mechanical flexibility of the sheets allow new sensor designs and put 2D materials at the forefront of all the candidates for wearable applications. When developing sensors for alcohol, the response time is an essential factor for many industrial and forensic applications, particularly when it comes to hand-held devices. Here, we review recent developments in the applications of 2D materials in sensing alcohols along with a study on parameters that affect the sensing capabilities. The review also discusses the strategies used to develop the sensor along with their mechanisms of sensing and provides a critique of the current limitations of 2D materials-based alcohol sensors and an outlook for the future research required to overcome the challenges.

A new and highly selective turn-on fluorescent sensor with fast response time for the monitoring of cadmium ions in cosmetic, and health product samples.

Cadmium (Cd) which is an extremely toxic could be found in many products like plastics, fossil fuel combustion, cosmetics, water resources, and wastewaters. It is capable of causing serious environmental and health problems such as lung, prostate, renal cancers and the other disorders. So, the development of a sensor to continually monitor cadmium is considerably demanding. Tetrakis(4-nitrophenyl)porphyrin, T(4-NO2-P)P, was synthesized and used as a new and highly selective fluorescent probe for monitoring cadmium ions in the "turn-on" mode. There was a linear relationship between fluorescence intensity and the concentration of Cd(II) in the range of 1.0×10(-6) to 1.0×10(-5)molL(-1) with a detection limit of 0.276µM. To examine the most important parameters involved and their interactions in the sensor optimization procedure, a four-factor central composite design (CCD) combined with response surface modeling (RSM) was implemented. The practical applicability of the developed sensor was investigated using real cosmetic, and personal care samples.

Ce (III) - Porphyrin Sandwich Complex Ce2(TPP)3: A Rod-Like Nanoparticle as a Fluorescence Turn-Off Probe for Detection of Hg (II) and Cu (II).

In this study the researcher reports a novel, one step synthesized rod-like nanoparticles of cerium (III)-tetraphenylporphyrin sandwich complex as a spectrofluorometric sensor to measure trace amount of Hg (II) and Cu (II) metal ions. Moreover, the synthesized fluorescent probe was able to detect higher amounts (>10(-4) M) of Hg (II) in aqueous media by changing the color which can also be used as a selective mercury naked-eye sensor. The selectivity and sensitivity of the sensor based on its fluorescence quenching in the presence of Hg (II) and Cu (II) were studied according to the Stern-Volmer equation. The detection limit of the sensor was 16 nM for Hg (II) and about 2.34 µM for Cu (II) ions. Graphical Abstract Ce2(TPP)3 sandwich complex application as a fluorescent probe for measuring trace amounts of mercury and copper in real samples.

Cd-Cysteine Nanorods as a Fluorescence Sensor for Determination of Fe (III) in Real Samples.

A new Cd-Cysteine complex nanorods (Cd-Cys NRs) were synthesized in one step at room temperature, and its morphology, structure and spectral properties were characterized by transmission electron microscopy (TEM), elemental analysis (EA), X-Ray diffraction (XRD), solid state and normal UV-Vis, Fourier transform infrared (FTIR) and spectrofluorometry. The developed Cd-Cys NRs were used as a fluorescence sensor for detection of Fe (III) in different aqueous matrices. The selectivity and sensitivity of the fabricated nano-sensor based on its fluorescence quenching in the presence of Fe (III) were probed according to the Stern-Volmer equation. The detection limit of the method was in micro-molar per liter range. Cd-Cys NRs response tested in different complex samples such as Rosemary plant leaves, exhibited a well-defined response. Anticoagulation measurements were performed to evaluate their blood biocompatibility.