Simulated Urine Research Articles

Development and pre-clinical evaluation of a Zika virus diagnostic for low resource settings.

Zika virus (ZIKV) is a re-emerging flavivirus that poses a significant public health threat. ZIKV exhibits a wide array of non-vector borne human transmission routes, such as sexual transmission, transplacental transmission and blood transfusion. Detection and surveillance of ZIKV is considered paramount in prevention of major outbreaks. With the majority of cases reported in low-resource locations, simple, low-cost detection methods are considered highly desirable. Here we have developed a sensitive and specific ZIKV diagnostic using reverse transcription recombinase-aided amplification (RT-RAA) coupled with lateral flow detection (LFD) targeting a highly conserved region of the ZIKV NS1 gene. We show our rapid, isothermal-ZIKV-diagnostic (Iso-ZIKV-Dx) can detect 500 copies of synthetic ZIKV RNA/μL in under 30 min at a constant 39°C. Using simulated urine samples, we observed that Iso-ZIKV-Dx also detects as low as 34.28 RNA copies/reaction of ZIKV (MR766 strain). Specificity testing confirmed that our test does not detect any co-circulating flaviviruses (dengue, West Nile, Japanese encephalitis, Murray Valley encephalitis and yellow fever viruses) or chikungunya virus. Sample processing results show complete inactivation of ZIKV (MR766 strain) in 5 min at room temperature using our novel viral RNA sample preparation reagent. Furthermore, lateral flow strips testing demonstrates positive diagnoses in as little as 5 min in running buffer. Contrary to conventional RT-qPCR, our Iso-ZIKV-Dx does not require expensive machinery, specialised laboratory settings or extensively trained personnel. Pre-clinical evaluation demonstrates that our test exhibits robust, in-field capabilities without compromising sensitivity or specificity. When compared to the gold-standard RT-qPCR, our Iso-ZIKV-Dx test offers an array of applications that extend beyond diagnostics alone, including potential for surveillance and monitoring of ZIKV vector competency.

A Study on Simulated Urine Absorption Behaviour of Kapok-Cotton Blended Nonwoven Web

ABSTRACT Textile waste materials such as chemical-based diapers are responsible for aggravating environmental pollution. It usually takes years to degrade naturally. The world is in constant need of some green alternative solutions without compromising on product performance. Cellulosic materials being highly absorbent and biodegradable in nature such as cotton, Kapok, jute, banana etc. have the potential to replace these synthetic materials. The present study investigates the simulated urine absorption and retention characteristics of 100% cotton and Kapok-cotton blended webs. The morphological characteristics of raw, scoured and rewetted Kapok fiber were first studied. The hollow Kapok fiber lumen was found to have collapsed after scouring. However, it regained its shape after re-wetting in simulated urine. Absorption capacity was found to be maximum at 50:50 Kapok-cotton ratio in the nonwoven web. Statistically, the t-test also corroborates the same result at a 5% significance level. The absorption rate (g/s) and retention (%) were also maximum for the same blend. With an increase in external pressure, the liquid retention was reduced. On comparing a 50:50 Kapok-cotton blended with a 100% cotton nonwoven fibrous web, the absorption capacity, rate, and retention are increased by 26.1%, 300%, and 13.5%, respectively.

Turn-off luminescence sensing activities of amide-functionalized Zn-MOF toward biomarker (2-methoxyethoxy)acetic acid and antibiotic tetracycline

One Zn-MOF, namely, {[Zn(L)0.5(bpy)0.5(H2O)]·H2O·DMF}n (LCU-123), was synthesized from an amide-containing carboxylic acid N,N’’-(3,5-dicarboxylphenyl)benzene-1,4-dicarbox-amide (H4L) and 4,4’-bipyridine. The carboxylate ligand and 4,4’-bipyridine connect Zn(II) centers to form two-dimensional layers. Adjacent 2D layers are stacked to form a stable supramolecular structure with one-dimensional channels. Luminescence measurements indicated that the complex exhibited excellent multiple sensing activities toward biomarker (2-methoxyethoxy)acetic acid (MEAA) and antibiotic tetracycline hydrochloride (TC). It is worth noting that the LOD for MEAA and TC were as low as 18.030 and 0.552 μM, respectively. Investigations on the sensing mechanism indicated that the luminescence quenching of MEAA was due to the weak interaction and dynamic quenching mechanism, while the quenching sensing of TC was attributed to competitive absorption and PET effect. The recoveries for the sensing analytes are satisfactory from 102.8 to 109.8% (toward MEAA in simulated urine) and 99.3 to 106.0% (toward TC in water), indicating the complex possesses acceptable reliability for monitoring the above two analytes in real samples.

Establishment and application of a point-of-care testing and diagnosis method for early immediate expression gene IE1 of cytomegalovirus in maternal urine based on isothermal amplification

BackgroundHuman Cytomegalovirus virus (HCMV) is a worldwide virus that causes no serious symptoms in most adults. However, HCMV infection during pregnancy, it may lead to a series of serious complications, such as hearing loss, mental retardation, visual impairment, microcephaly and developmental retardation. AimThe aim of this study was to develop a simple, low dependence on equipment and accurate method for HCMV detection based on the recombinase polymerase amplification (RPA) and lateral flow chromatography strip (LFS) reading. MethodsIn order to meet the feasibility of HCMV early screening, three pairs of RPA primers were designed based on the UL123 gene encoding IE1, which was expressed immediately in the early stage of HCMV. In order to improve the specificity of the reaction and satisfy the visual detection, a specific probe was designed to insert THF site between upstream and downstream primers, fluorescein isothiocyanate (FITC) and C3spacer were used to modify the 5′ end and the 3′ end respectively, and Biotin was used to modify the 5′ end of the reverse primer. HCMV standard strain AD169 was enriched by ARPE-19 cells culture, and its genome was extracted. The primers and probes were screened by RPA-LFS test, and the optimal reaction temperature and time were determined The specificity was verified in different viruses, bacteria and parasites. The standard curve was drawn based on the constructed recombinant plasmid of pMD18T-HCMV-UL123 and used for HCMV genomic DNA quantification and determination of the detection sensitivity. Urine samples from artificial HCMV contamination or clinical collection were prepared to evaluate the consistency with the results of real-time quantitative PCR. ResultsThe results showed that the primers and probes for HCMV RPA-LFS detection based on UL123 gene were successfully screened, the amplification of HCMV genomic DNA with as low as 30 copies could be completed at 37 °C within 15 min, it did not react with Human herpesvirus 1, Streptococcus pyogenes, Candida albicans, Listeria monocytogenes, Y. enterocolitica, Klebsiella Pneumoniae, Enterobacter cloacae, Citrobacter freundii, Vibrio alginnolyfificus, Vibrio parahaemolyticus, S. typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa and Trichomonas vaginalis. The positive rate of PCR was 96.67 % in 30 simulated urine samples and 100 % in 127 clinical urine samples with the same UL123 gene detection. ConclusionsTo sum up, we developed a diagnostic method for HCMV based on UL123 gene combined with RPA and LFS, which is low dependent on equipment, fast, sensitive and specific, provide reference for point-of-care testing HCMV in grass-roots laboratories and remote areas.

One-step Nonenzymatic Electrochemical Sensor for the Detection of Sarcosine Using Nanozyme Glutathione Copper Complex

Background: The present study aims to develop the use of glutathione copper complex for the detection of sarcosine, a marker for prostate cancer. The glutathione-copper complex was successfully synthesized at room temperature and characterized using FTIR, UV, and Scanning Electron Micrograph. Methods: The structure of the glutathione copper complex was found to be a 1:2 Metal: Ligand ratio. The cyclic voltammogram for the glutathione-copper complex modified electrode showed an oxidation peak around -0.037 V, which indicates the irreversible oxidation of copper ions. The addition of sarcosine decreased the oxidation potential of the glutathione copper complex indicating the ability of the working electrode, for the detection of sarcosine in the sample using differential pulse voltammetry. Results: The results indicated that the glutathione-copper complex modified electrode revealed good sensitivity, selectivity, and linearity against the detection of sarcosine in the range from 0.1 μM to 2.5 μM. The LOD and LOQ were calculated using a linear prediction model, the data obtained from differential pulse voltammetry technique for known and simulated urine samples was 0.72 μM, 5.13 μM, and 1.45 μM, 39.94 μM, respectively. The sensitivity for the developed working electrode obtained for the known and simulated sample was 0.0567 μA/μM and 0.02913 μA/μM, respectively. Conclusion: Thus, we concluded that the glutathione copper complex decorated glassy carbon electrode is a good candidate for the detection of sarcosine with good selectivity and sensitivity for real-time monitoring.

Enhancing efficient reclaim of phosphorus from simulated urine by magnesium-functionalized biochar: Adsorption behaviors, molecular-level mechanistic explanations and its potential application

Magnesium-functionalized Magnolia grandiflora Linn leaf-derived biochar (MBC) capable of efficiently reclaiming phosphorus from urine was synthesized by slow co-pyrolysis. Four adsorption kinetic and seven adsorption isotherm models were fitted to the batch adsorption and desorption experimental data, and it was found that pseudo-first-order kinetic model and multilayer model with saturation best described the phosphate-phosphorus (PO43−-P) adsorption process by MBC. MBC and phosphorus-saturated MBC (P-MBC) were found to offer outstanding phosphorus adsorption and slow release properties, respectively. Based on material characterization, statistical physics, adsorption energy distribution and statistical thermodynamics, a multi-ionic, inclined orientation, entropy-driven spontaneous endothermic process of MBC on PO43−-P was proposed, involving physicochemical interactions (porous filling, electrostatic attraction, ligand exchange and surface precipitation). Further, seed germination and early seedling growth experiments proved that P-MBC can be used as a slow-release fertilizer. Overall, MBC offers prospective applications as an efficient phosphorus adsorbent and then as a slow-release fertilizer.

Electroanalytical Measurement of Steroid Hormone with Carbon Electrode Sensor

Cortisol is a vital steroid hormone that has been known as the “stress hormone,” which is elevated during times of high stress and anxiety. The improved detection of cortisol is critically important as it will help further our understanding of stress during several physiological states. Several methods exist to detect cortisol, however, they suffer from low biocompatibility, spatiotemporal resolution, and are relatively slow. In this study, we developed an assay to measure cortisol with carbon fiber microelectrodes (CFMEs) and fast-scan cyclic voltammetry (FSCV). FSCV is typically utilized to measure small molecule neurotransmitters by producing a readout CV for the specific detection of biomolecules on a fast, subsecond timescale with biocompatible CFMEs. It has seen enhanced utility in measuring peptides and other larger and more complex molecules. We developed a waveform to electro-reduce cortisol at the surface of CFMEs. The sensitivity of cortisol was found to be 5 nA/uM and was adsorption controlled on the surface of CFMEs and stable over several hours. Cortisol was co-detected with several other biomolecules such as dopamine and serotonin, and the waveform was fouling resistant to repeated injections of cortisol on the surface of the CFMEs. Furthermore, we also measured exogenously applied cortisol onto brain tissue and simulated urine to demonstrate biocompatibility and potential use in vivo. The specific biocompatible detection of cortisol with high spatiotemporal resolution will help further elucidate its biological significance and further understand its physiological importance in the brain.

Pillar[n]MaxQ sensing ensemble: Application to world anti-doping agency banned substances

The molecular recognition properties of two pillar[n]arene sulfates (P[5]AS and P[6]AS) toward a panel of world anti-doping agency banned substances (1–11) were investigated by a combination of isothermal titration calorimetry, 1H NMR spectroscopy, and molecular modelling. Subsequently a sensing ensemble based on indicator displacement was created using the P[5]AS•lucigenin and P[6]AS•Hoechst 33258 complexes which allowed differentiation among the analytes with 90% accuracy. The assay was extended to allow the quantitation of pseudoephedrine in simulated urine samples with a limit of quantitation that is 30-fold below the WADA threshold.

Facing the treatment of polymedicated effluents using gaseous ozone electrochemically generated

The degradation of antibiotics in hospital urine, as alternative to reduce the chemical risk of hospital effluents, is evaluated by gaseous ozone electrochemically generated in Polymer Electrolyte Membrane (PEM) cells. Firstly, the influence of the current density in the electrochemical step is evaluated. The results indicate that ozone gas with rates ranging from 0.034 to 1.111 mg O3 min−1 can be produced by applying current densities of 21–125 mA cm−2. Then, the degradation of Penicillin G (Pen G) by electrochemically generated ozone is evaluated. Results show that the degradation rate is dependent on the ozone dose flow rate and the aeration system plays a crucial role in enhancing the efficiency of the ozonation process by reducing the limitations associated with gas-liquid mass transfer. Under the optimal conditions, using an ozone dosage of 1.111 mg O3 min−1, 100 % efficiency of Pen G (50 mg dm−3) removal in hospital urine is achieved after 13 min, resulting in a ratio of 1.04 mg Pen G removed per mg O3 supplied. Finally, the efficiency of electrogenerated gaseous ozone for treating a simulated polymedicated hospital urine (using data from the University Hospital Complex of Albacete (Spain) as case of study) is tested. The findings suggest that the chemical risk associated with hospital urine is mitigated (reducing antibiotic activity by 100 %) by breaking down pharmaceutical compounds into simpler molecules that no longer possess antibiotic properties. Degradation efficiencies over 2 g (kWh)−1 make of this treatment a cost-effective alternative to treat hospital effluents.

Intelligent Colorimetric Sensor for Discriminative Detection of Pd2+/Pd0 and PPh3 at Different Wavelength Readouts

AbstractIn this report, we presented our results on a recognition of multiple analytes using trisubstituted PDI‐based chemosensor DNP in 50 % HEPES buffered‐CH3CN solution. Upon addition of Pd2+ or Pd0, DNP showed near IR ratiometric changes (A759nm/A560nm) with detection limit of 283 nM and 190 nM, respectively. These spectroscopic changes are associated with color change from violet to light yellow (de‐propargylation). The de‐propargylation reaction of DNP is faster in the presence of Pd2+ than Pd0. Upon addition of PPh3, DNP resulted in appearance of new bands at 615 and 698 nm with decrease of absorbance intensity at 560 nm with detection limit of 349 nM. Two isosbestic points at 504 nm and 600 nm was observed. This change is associated with color changes from violet to blue. DNP coated TLC‐strips can be used for the detection of 4×10−4 M Pd0 and PPh3. We have demonstrated the practical application of DNP (i) for the detection of Pd0 in live A549 cells and (ii) for detection of Pd2+/Pd0 in simulated urine (10 %) samples with recovery of (>98±5 %).

Excretion Detection Systems with Gas Sensors - Development of Excretion Detection Device with Non-Suction Utilizing Floor Cushion –

In this paper, we report the development and evaluation of an excretion detection device which is to be used with a cushion. Remarkably, the device does not require air suction and can be used during the daytime. The device can be placed on a chair or wheelchair and used whenever a cared person sits. Reflecting on the views of caregivers and the observations of the cared persons, the device was designed to be as thin and flexible as possible. In experiments to evaluate the response, it was confirmed to respond not only to simulated urine but also to actual excrement. From the results of the clinical experiments, the excretion detection model achieved an accuracy rate of 76%. Although this figure is close to the approximately 80% accuracy rate of an existing product H, it must be kept in mind that this accuracy rate is limited to urination owing to the limited training data in this study. These findings suggest that the device used with a cushion provides a valid means of excretion detection during daytime hours in a non-wearing and non-invasive manner, although its use is currently limited to urination.

Carbon Electrode Sensor for the Measurement of Cortisol with Fast-Scan Cyclic Voltammetry.

Cortisol is a vital steroid hormone that has been known as the "stress hormone", which is elevated during times of high stress and anxiety and has a significant impact on neurochemistry and brain health. The improved detection of cortisol is critically important as it will help further our understanding of stress during several physiological states. Several methods exist to detect cortisol; however, they suffer from low biocompatibility and spatiotemporal resolution, and they are relatively slow. In this study, we developed an assay to measure cortisol with carbon fiber microelectrodes (CFMEs) and fast-scan cyclic voltammetry (FSCV). FSCV is typically utilized to measure small molecule neurotransmitters by producing a readout cyclic voltammogram (CV) for the specific detection of biomolecules on a fast, subsecond timescale with biocompatible CFMEs. It has seen enhanced utility in measuring peptides and other larger compounds. We developed a waveform that scanned from -0.5 to -1.2 V at 400 V/s to electro-reduce cortisol at the surface of CFMEs. The sensitivity of cortisol was found to be 0.87 ± 0.055 nA/μM (n = 5) and was found to be adsorption controlled on the surface of CFMEs and stable over several hours. Cortisol was co-detected with several other biomolecules such as dopamine, and the waveform was fouling resistant to repeated injections of cortisol on the surface of the CFMEs. Furthermore, we also measured exogenously applied cortisol into simulated urine to demonstrate biocompatibility and potential use in vivo. The specific and biocompatible detection of cortisol with high spatiotemporal resolution will help further elucidate its biological significance and further understand its physiological importance and impact on brain health.

Soil denitrification response to increased urea concentration constrains nitrous oxide emissions in a simulated cattle urine patch

Soil denitrification response to increased urea concentration constrains nitrous oxide emissions in a simulated cattle urine patch

Sodium Salt of Partially Carboxymethylated Sodium Alginate-Graft-Poly(Acrylonitrile): II Superabsorbency, Salt Sensitivity and Swelling Kinetics of Hydrogel, H-Na-PCMSA-g-PAN.

The water absorption measurements of a novel superabsorbent anionic hydrogel, H-Na-PCMSA-g-PAN, has been reported first time in water with a poor conductivity, 0.15 M saline (NaCl, CaCl2, and AlCl3) solutions, and simulated urine (SU) solutions at various times. The hydrogel has been prepared by the saponification of the graft copolymer, Na-PCMSA-g-PAN (%G = 316.53, %GE = 99.31). Results indicated that as compared to the swelling capacity values evaluated in water with a poor conductivity, the ability of the hydrogel to swell in various saline solutions with the same concentration is significantly reduced at all different durations. The swelling tends to be Na+ > Ca2+ > Al3+ at the same saline concentration in the solution. Studies of the absorbency in various aqueous saline (NaCl) solutions also revealed that the swelling capacity decreased as the ionic strength of the swelling medium rose, which is consistent with the experimental results and Flory's equation. Furthermore, the experimental results strongly suggested that second-order kinetics governs the swelling process of the hydrogel in various swelling media. The swelling characteristics and equilibrium water contents for the hydrogel in various swelling media have also been researched. The hydrogel samples have been successfully characterized by FTIR to show the change in chemical environment to COO- and CONH2 groups after swelling in different swelling media. The samples have also been characterized by SEM technique.

A Study of the Detection of SARS-CoV-2 by the Use of Electrochemiluminescent Biosensor Based on Asymmetric Polymerase Chain Reaction Amplification Strategy.

A new and reliable method has been constructed for detecting severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) open reading frames 1ab (ORF1ab) gene via highly sensitive electrochemiluminescence (ECL) biosensor technology based on highly efficient asymmetric polymerase chain reaction (asymmetric PCR) amplification strategy. This method uses magnetic particles coupled with biotin-labeled one complementary nucleic acid sequence of the SARS-CoV-2 ORF1ab gene as the magnetic capture probes, and [Formula: see text]-labeled amino-modified another complementary nucleic acid sequence as the luminescent probes, and then a detection model of magnetic capture probes-asymmetric PCR amplification nucleic acid products-[Formula: see text]-labeled luminescent probes is formed, which combines the advantages of highly efficient asymmetric PCR amplification strategy and highly sensitive ECL biosensor technology, enhancing the method sensitivity of detecting the SARS-CoV-2 ORF1ab gene. The method enables the rapid and sensitive detection of the ORF1ab gene and has a linear range of 1-[Formula: see text] copies/[Formula: see text], a regression equation of [Formula: see text] = [Formula: see text] + 2919.301 ([Formula: see text] = 0.9983, [Formula: see text] = 7), and a limit of detection (LOD) of 1 copy/[Formula: see text]. In summary, it can meet the analytical requirements for simulated saliva and urine samples and has the benefits of easy operation, reasonable reproducibility, high sensitivity, and anti-interference abilities, which can provide a reference for developing efficient field detection methods for SARS-CoV-2.

CRISPR-assisted test for Schistosoma haematobium

Schistosomiasis is a major neglected tropical disease targeted for elimination as a public health issue by 2030, however there is an urgent need for more sensitive and specific diagnostic tests suitable to resource-limited settings. Here we developed CATSH, a CRISPR-assisted diagnostic test for Schistosoma haematobium, utilising recombinase polymerase amplification, Cas12a-targeted cleavage and portable real-time fluorescence detection. CATSH showed high analytical sensitivity, consistent detection of a single parasitic egg and specificity for urogenital Schistosoma species. Thanks to a novel CRISPR-compatible sample preparation developed using simulated urine samples containing parasitic eggs, CATSH had a sample-to-result within 2 h. The components of CATSH can be lyophilised, reducing cold chain dependence and widening access to lower and middle-income countries. This work presents a new application of CRISPR diagnostics for highly sensitive and specific detection of parasitic pathogens in remote areas and could have a significant impact on the elimination of neglected tropical diseases.

Labile carbon inputs support the recovery of bacterial communities, but not fungal communities, from a simulated bovine urine event

Inputs of carbon to soil may be used to stimulate microbial growth and immobilize excess nitrogen from sources such as livestock urine. However, the growth responses of microbial taxa to carbon inputs under conditions of excess soil nitrogen remain poorly understood. Using DNA metabarcoding and a field-based soil lysimeter experiment, we characterised the temporal responses (up to 112 days) of bacterial and fungal communities to a simulated bovine urine event plus inputs of labile carbon (sucrose) at two concentrations. Fungal communities were impacted more strongly than bacterial communities by carbon inputs following the simulated urine event, with more variable responses among taxa. Chytridiomycota and Glomeromycota richness were most negatively affected, and Tremellomycetes richness most positively affected, by carbon inputs. A minority of fungal ASVs had greatly increased proportional abundances in response to carbon, while fungal trophic composition became highly dominated by saprotrophs by the experiment end. Bacterial taxa showed consistent trends of declining (to about 14 days) and recovering (to 112 days) richness in response to urine and carbon inputs, but carbon-related evenness and proportional abundance trends varied between taxa. Proportional abundances of Actinobacteria, Bacteroidetes, Betaproteobacteria, and Gammaproteobacteria increased in response to carbon, whereas proportional abundances of Acidobacteria, candidate division WPS-1, Planctomycetes, Deltaproteobacteria, and Verrucomicrobia decreased. These results show that labile carbon inputs to limit nitrate leaching support the recovery of bacterial communities to bovine urine events but may have long-term impacts on fungal community composition and function, with potential consequences for soil food webs, carbon sequestration, and agricultural productivity.

Insights into the Safety and Versatility of 4D Printed Intravesical Drug Delivery Systems.

This paper focuses on recent advancements in the development of 4D printed drug delivery systems (DDSs) for the intravesical administration of drugs. By coupling the effectiveness of local treatments with major compliance and long-lasting performance, they would represent a promising innovation for the current treatment of bladder pathologies. Being based on a shape-memory pharmaceutical-grade polyvinyl alcohol (PVA), these DDSs are manufactured in a bulky shape, can be programmed to take on a collapsed one suitable for insertion into a catheter and re-expand inside the target organ, following exposure to biological fluids at body temperature, while releasing their content. The biocompatibility of prototypes made of PVAs of different molecular weight, either uncoated or coated with Eudragit®-based formulations, was assessed by excluding relevant in vitro toxicity and inflammatory response using bladder cancer and human monocytic cell lines. Moreover, the feasibility of a novel configuration was preliminarily investigated, targeting the development of prototypes provided with inner reservoirs to be filled with different drug-containing formulations. Samples entailing two cavities, filled during the printing process, were successfully fabricated and showed, in simulated urine at body temperature, potential for controlled release, while maintaining the ability to recover about 70% of their original shape within 3 min.

Two Co-Based Metal–Organic Framework Isomers with Similar Metal-Carboxylate Sheets: Turn-On Ratiometric Luminescence Sensing Activities toward Biomarker N-Acetylneuraminic Acid and Discrimination of Ga3+ and In3+

Two supramolecular Co-MOF isomers, namely, {[Co(L)0.5(m-bimb)]·3H2O}n (LCU-115) and {[Co(L)0.5(p-bimb)]·3H2O}n (LCU-116), were synthesized from an amide-containing carboxylic acid N,N″-(3,5-dicarboxylphenyl)benzene-1,4-dicarboxamide (H4L) and two flexible positional isostructural N-containing ligands m-bimb and p-bimb (m-bimb = 1,3-bis((1H-imidazol-1-yl)methyl)benzene; p-bimb = 1,4-bis((1H-imidazol-1-yl)methyl)benzene). The carboxylate ligands connect Co(II) centers to form 2D metal-carboxylate sheets, which are extended further by m-bimb and p-bimb to form a 2D bilayer with parallel stacking (LCU-115) and a 3D framework (LCU-116), respectively. Luminescence measurements indicated that these two complexes exhibited interesting multiresponsive sensing activities toward pH, biomarker N-acetylneuraminic acid, and trivalent cations Ga3+/In3+. They show highly sensitive turn-on fluorescence responses in the acidic range and can also be regarded as on-off-on vapoluminescent sensors to typical acidic and basic gases HCl and Et3N. It is worth noting that these complexes have excellent turn-on ratiometric fluorescence sensing ability for N-acetylneuraminic acid (NANA) with detection limits as low as 7.39 and 8.06 μM, respectively. Furthermore, they were successfully applied for the detection of NANA in simulated urine and serum samples with satisfactory results. For ion detection, LCU-116 could detect both Ga3+ and In3+, while LCU-115 could distinguish Ga3+ from In3+ with the latter showing luminescence quenching. The sensing mechanism was investigated in detail by XRD, UV-vis, EDS, XPS, SEM, and TEM. The results of interday and intraday precision studies gave low RSD values in the range of 1.19-3.53%, ascertaining the reproducibility of these sensors. The recoveries for the sensing analytes in simulated urine/serum or real water are satisfactory from 96.7 to 103.3% (toward NANA) and 96.6 to 115.0% (toward Ga3+ and In3+), indicating that these two complexes also possess acceptable reliability for monitoring in real samples. The results indicated that the supramolecular isomers LCU-115 and LCU-116 are promising material candidates for application in biological and environmental monitoring.

Use of newly synthetized magnetic Fe3O4 nanoparticles modified with hexadecyl trimethyl ammonium bromide for the sensitive analysis of antidepressant drugs, duloxetine and vilazodone in wastewater and urine samples.

A new enrichment and determination method involving HPLC-DAD analysis following magnetic solid-phase extraction (MSPE) was developed to detect trace amounts of two antidepressant drugs, namely, duloxetine (DUL) and vilazodone (VIL). In this study, a solid-phase sorbent was newly synthesized for use in the MSPE and its characterization was carried out by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray diffraction (XRD) techniques. In this proposed method, DUL and VIL molecules were enriched using newly synthesized magnetic-based nanoparticles in the presence of pH 10.0 buffer and desorbed with acetonitrile to a smaller volume prior to chromatographic determinations. After experimental variables were optimized, the VIL and DUL molecules were analyzed at wavelengths of 228 nm for DUL and 238 nm for VIL with isocratic elution of methanol, trifluoroacetic acid (TFA) (0.1%), and acetonitrile (10 : 60 : 30). The detection limits obtained under optimized conditions were 1.48 ng mL-1 and 1.43 ng mL-1, respectively. The %RSD values were found to be lower than 3.50% with model solutions containing 100 ng mL-1 (N:5). Finally, the developed method was successfully applied to wastewater samples and simulated urine samples, and quantitative results were obtained in the recovery experiments.