High Selectivity Research Articles

CRISPR-Cas13a-Based Lateral Flow Assay for Detection of Bovine Leukemia Virus

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL), which presents worldwide prevalence. BLV caused substantial economic loss in China around the 1980s; then, it could not be detected for some time, until recently. Due to its latent and chronic characteristics, the efficient and accurate detection of BLV is of utmost significance to the timely implementation of control measures. Therefore, this study harnessed the recombinase-aided amplification (RAA), clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 13a (Cas13a) technology, and lateral flow (LF) strips to develop an efficient method for detection of BLV. In this method, isothermal amplification of the targeted pol gene is performed at 37 °C with a detection threshold of 1 copy/µL, and the procedure is completed in 100 min. This assay demonstrated high selectivity for BLV, as indicated by the absence of a cross-reaction with six common bovine pathogens. Remarkably, 100 blood samples from dairy cows were tested in parallel with a conventional quantitative polymerase chain reaction (qPCR) and this method and the results showed 100% agreement. Furthermore, this method exhibited good repeatability. In conclusion, in this study, we established a sensitive and specific method for BLV detection, which shows promise for application in BLV surveillance.

Effects of a novel HDAC6-selective inhibitor's radiosensitization on cancer cells.

The radiation sensitivity of tumor cells is a critical determinant of their therapeutic response to radiotherapy. Histone deacetylase 6 (HDAC6), beyond its known role in modulating tubulin acetylation and influencing cell motility, is also involved in the DNA damage response, potentially enhancing tumor cell radiosensitivity. Targeted HDAC6 inhibitors have shown substantial promise in preclinical studies aimed at increasing radiosensitivity and inhibiting cellular migration. A new HDAC inhibitor, named OXHA, was designed by substituting the phenyl cap of SAHA with an N,5-diphenyloxazole-2-carboxamide group. The inhibitory activity of OXHA was evaluated via in vitro enzymatic assays. Its effects on tumor cell migration and radiosensitization potential were assessed using scratch wound healing assays, micronucleus formation, and clonogenic survival assays. Enzymatic assays confirmed OXHA's selective inhibition of HDAC6. Compared to SAHA, OXHA significantly increased α-tubulin acetylation while minimally impacting histone H3 acetylation, indicating a high selectivity for HDAC6. In combination with X-ray irradiation, OXHA markedly impaired wound healing in A549 and HepG2 cells, enhanced micronucleus formation, and reduced clonogenic survival across multiple tumor lines. OXHA exhibits potent and selective HDAC6 inhibition, effectively impeding tumor cell migration and enhancing radiosensitivity across multiple cell lines. These findings suggest that OXHA has strong potential as a therapeutic strategy to improve radiotherapy efficacy.

Fibrous Pb(II)‐Based Coordination Polymer Operable as a Photocatalyst and Electrocatalyst for High‐Rate, Selective CO2‐to‐Formate Conversion

AbstractA nonporous [Pb(tadt)]n (tadt = 1,3,4‐thiadiazole‐2,5‐dithiolate) coordination polymer, KGF‐9, with a 2D infinite (−Pb−S−)n structure has been previously reported as a precious‐metal‐free photocatalyst for selective CO2‐to‐formate conversion under visible light. In the present work, a microwave (MW)‐assisted solvothermal reaction is used to synthesize KGF‐9 with improved physicochemical properties and catalytic activity. Compared with KGF‐9 prepared by the previously reported methods, that prepared by the new synthesis route exhibited a greater specific surface area, greater crystallinity, and greater photoconductivity. These improved properties led to a drastic increase of the apparent quantum yield (AQY) for selective formate production, from 2.6 to 25% at 400 nm; this AQY represents a record‐high value among reported heterogeneous photocatalysts for CO2‐to‐formate conversion. Interestingly, the AQY for formate production is unchanged irrespective of the light intensity (0.04–14 mW cm−2), indicating little contribution of charge accumulation in the bulk during the reaction (i.e., indicating efficient charge transport to surface reactants). When composited with Ketjen Black, KGF‐9 enabled the electrochemical conversion of CO2 to formate in aqueous solution while maintaining a high selectivity. A high‐rate reduction of CO2 to formate with a total absolute current density of 200–300 mA cm−2 is achieved, with a Faradaic efficiency (FE) of >90%.

Photo(Multicomponent) Reaction of Quinoxalin‐2(1H)‐ones with CBrCl3 and Styrenes by Mes‐Acr‐MeClO4

AbstractIn this study, we explored the use of Mes‐Acr‐MeClO4 as a visible light photocatalyst for multicomponent reactions involving quinoxalin‐2(1H)‐ones with CBrCl3 and styrene. The method showcases regioselective functionalization of quinoxalin‐2(1H)‐ones in a three‐component system, forming two C─C bonds in one pot. Mechanistic investigations suggest a radical‐mediated pathway, initiated by the photoexcitation of Mes‐Acr‐MeClO4, followed by halogen atom abstraction from CBrCl3. This approach provides a versatile and sustainable route for quinoxalin‐2(1H)‐one functionalization, with Mes‐Acr‐MeClO4 effectively facilitating the photocatalyzed multicomponent reaction under mild conditions and visible light irradiation, yielding high selectivity and efficiency.

Boosting Propane Dehydrogenation to Propylene via Electron Hole‐Hydrogen Coupling on Cobalt Metal Surface

AbstractNonoxidative dehydrogenation of propane is useful for the high selectivity to propylene but is suffering from the heavy coke deposition on the catalyst surface. Herein, we present a proof‐of‐concept application of a hole‐hydrogen (H) couple on a metallic cobalt surface to decrease the deactivation rate. The coupled H atoms on the Cobalt (Co) surface, partially resulting from propane dehydrogenation, enabled the desorption of propylene to avoid deep hydrogenolysis and coke deposition and realize selective and durable propylene production, while conventional Co metal‐based catalysts do not generate propylene. The optimized hole‐H coupled Co catalyst provided a low deactivation rate (0.0036 h−1) and a high turnover frequency (55.6 h−1) for propylene production with a high propane flux (48 vol.% C3H8 in gas feeds) at 550 °C.

Electrochemical Upgrading of Waste Polylactic Acid Plastic for the Coproduction of C2 Chemicals and Green Hydrogen

Tandem alkali-catalyzed hydrolysis and alkaline electrolysis have gradually become appealing avenues for the reformation of polyester plastics into high-value-added chemicals and green hydrogen with remarkable environmental and economic benefits. In this study, an electrochemical upcycling strategy was developed for the electrocatalytic oxidation of polylactic acid (PLA) hydrolysate into valued C2 chemicals (i.e., acetate) and hydrogen fuel using N, P-doped CuOx nanowires (NW) supported on nickel foam (NF) as the electrocatalyst. This 3D well-integrated catalyst was easily prepared from a Cu(OH)2 NW/NF precursor with Saccharomycetes as a green and safe P and N source. The electrocatalyst can efficiently catalyze the lactate monomer derived from the hydrolysis of PLA waste to acetate with high selectivity and exhibits a lower onset potential for the lactate oxidation reaction (LOR) than for water oxidation, saving 224 mV to deliver a current density of 30 mA/cm2. The experimental results reveal that the plausible pathway of the LOR on these CuOx NW involves oxidation and subsequent decarboxylation. Divalent copper species have been verified to be active sites for LOR via in situ Raman spectroscopy.

Prompting CO2 Electroreduction to Ethanol by Iron Group Metal Ion Dopants Induced Multi‐sites at the Interface of SnSe/SnSe2 p–n Heterojunction

AbstractThe development of non‐copper‐based materials for CO2 electroreduction to ethanol with high selectivity at large current density is highly desirable, but still a great challenge. Herein, we report iron group metal ions of M2+ (M=Fe, Co, or Ni)‐doped amorphous/crystalline SnSe/SnSe2 nanorod/nanosheet hierarchical structures (a/c‐SnSe/SnSe2) for selective CO2 electroreduction to ethanol. Iron group metal ions doping induces multiple active sites at the interface of M2+‐doped SnSe/SnSe2 p‐n heterojunction, which strengthens *CO intermediate binding for further C−C coupling to eventual ethanol generation. As a representative, Fe9.0%‐a/c‐SnSe/SnSe2 exhibits an ethanol Faradaic efficiency of 62.7 % and a partial current density of 239.0 mA cm−2 at −0.6 V in a flow cell. Moreover, it can output an ethanol Faradaic efficiency of 63.5 % and a partial current density of 201.2 mA cm−2 with a full‐cell energy efficiency of 24.1 % at 3.0 V in a membrane electrode assembly (MEA) electrolyzer. This work provides insight into non‐Cu based catalyst design for stabilizing the key intermediates for selective ethanol production from CO2 electroreduction.

Prompting CO2 Electroreduction to Ethanol by Iron Group Metal Ion Dopants Induced Multi-sites at the Interface of SnSe/SnSe2 p-n Heterojunction.

The development of non-copper-based materials for CO2 electroreduction to ethanol with high selectivity at large current density is highly desirable, but still a great challenge. Herein, we report iron group metal ions of M2+ (M=Fe, Co, or Ni)-doped amorphous/crystalline SnSe/SnSe2 nanorod/nanosheet hierarchical structures (a/c-SnSe/SnSe2) for selective CO2 electroreduction to ethanol. Iron group metal ions doping induces multiple active sites at the interface of M2+-doped SnSe/SnSe2 p-n heterojunction, which strengthens *CO intermediate binding for further C-C coupling to eventual ethanol generation. As a representative, Fe9.0%-a/c-SnSe/SnSe2 exhibits an ethanol Faradaic efficiency of 62.7 % and a partial current density of 239.0 mA cm-2 at -0.6 V in a flow cell. Moreover, it can output an ethanol Faradaic efficiency of 63.5 % and a partial current density of 201.2 mA cm-2 with a full-cell energy efficiency of 24.1 % at 3.0 V in a membrane electrode assembly (MEA) electrolyzer. This work provides insight into non-Cu based catalyst design for stabilizing the key intermediates for selective ethanol production from CO2 electroreduction.

Isoreticular Contraction in Dicopper Paddle-Wheel-Based Metal-Organic Frameworks to Enhance C2H2/CO2 Separation.

Achieving a balance between high selectivity and uptake is a formidable challenge for the purification of acetylene from mixtures with carbon dioxide, particularly when seeking to maximize both C2H2 adsorption capacity and C2H2/CO2 separation selectivity in crystalline porous materials. In this study, leveraging the principles of reticular chemistry, we selected two tetracarboxylate-based linkers and combined them with Cu2+ ions to synthesize two isoreticular dicopper paddle-wheel-based metal-organic frameworks (MOFs): Cu-TPTC (terphenyl-3,3',5,5'-tetracarboxylic acid , H4TPTC) and Cu-ABTC (3,3,5,5-azobenzenetetracarboxylic acid, H4ABTC). The structural and sorption analyses revealed that Cu-ABTC, despite having slightly smaller pores due to the strategic replacement of a phenyl ring with an azo group between two tetratopic ligands, maintains high porosity compared to Cu-TPTC. Furthermore, Cu-ABTC outperforms Cu-TPTC in terms of C2H2 adsorption capacity (196 cm3 g-1 at 298 K and 1 bar) and C2H2/CO2 separation selectivity (16.5~5.6). These findings were corroborated by dynamic breakthrough experiments and computational modeling. This research highlights the potential of the isoreticular contraction strategy in enhancing MOFs for sophisticated gas adsorption and separation processes.

Interface-Engineered CuxO@Bi2MoO6 Heterojunctions to Inhibit Piezoelectric Screening Effect and Promote Double-Nanozyme Catalysis for Antibacterial Treatment.

Sonodynamic therapy is confronted with the low acoustic efficiency of sonosensitizers, and nanozymes are accompanied by intrinsic low catalytic activity. Herein, to increase the piezopotential of N-type piezoelectric semiconductors, the P-N heterojunction is designed to inhibit the piezoelectric screening effect (PSE) and increase electron utilization efficiency to enhance nanozyme activity. P-type CuxO nanoparticles are in situ grown on N-type piezoelectric Bi2MoO6 (BMO) nanoflakes (NFs) to construct heterostructured CuxO@BMO by interface engineering. CuxO deposition leads to lattice distortion of BMO NFs to improve piezoelectric response, and the strong interface electric field (IEF) suppresses PSE and increases piezopotential. The nonlocal piezopotential, local IEF, and glutathione (GSH) inoculation enhances electron-hole separation and increases peroxidase (POD)-like activity of BMO and GSH oxidase (GSHOx)-like activity of CuxO with high selectivity. The heterojunction formation causes the transfer and rearrangement of interface electrons, and the increased piezopotential accelerates electron transfer at interfaces with bacteria, thus increasing the production of reactive oxidative species and interfering with adenosine triphosphate synthesis. The heterostructured nanozymes produce abundant intracellular ·OH and achieve 4log magnitude reductions in viable bacteria and effective biofilm dispersion. This study elucidates integral mechanisms of nanozyme and acoustic catalysis and opens up a new way to synergize high piezopotential and nanozyme-catalyzed therapy.

High‐Selectivity Tandem Photocatalytic Methanation of CO2 by Lacunary Polyoxometalates‐Stabilized *CO Intermediate

AbstractStabilizing specific intermediates to produce CH4 remains a main challenge in solar‐driven CO2 reduction. Herein, g‐C3N4 is modified with saturated and lacunary phosphotungstates (PWx, x=12, 11, 9) to tailor the CO2 reduction pathway to yield CH4 in high selectivity. Increased lacuna of phosphotungstates leads to higher CH4 yield and selectivity, with a superior CH4 selectivity of 80 % and 40.8 μmol ⋅ g−1 ⋅ h−1 evolution rate for PW9/g‐C3N4. Conversely, g‐C3N4 and PWx alone show negligible CH4 production. The conversion of CO2 to CH4 follows a tandem catalytic process. CO2 is initially activated on g‐C3N4 to form *CO intermediates, meanwhile photogenerated electrons derived from g‐C3N4 transfer to PWx. Then the reduced PWx captures *CO, which is subsquently hydrogenated to CH4. With the injection of two photogenerated electrons, PW9 is capable of adsorbing and activating *CO. However, the reduced PW12 and PW11 are incapable of adsorbing *CO due to the small energy of occupied molecular orbitals, which is the reason for the poorer activity of PWx/g‐C3N4 (x=12, 11) compared with that of PW9/g‐C3N4. This work provides new insights to regulate highly selective CO2 photoreduction to CH4 by utilizing lacuna of polyoxometalates to enhance the interaction of metals in polyoxometalates with key intermediates.

Water-Induced Switching in Selectivity and Steric Control of Activity in Photochemical CO2 Reduction Catalyzed by RhCp*(bpy) Derivatives.

Photocatalytic reduction of CO2 to formic acid (HCOOH) was investigated in either organic or aqueous/organic media by employing three water-soluble [RhIIICp*(LH2)Cl]+ (LH2 = n,n'-dihydroxy-2,2'-bipyridine; n = 4, 5, or 6) in the presence of [Ru(bpy)3]2+, 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH) and triethanolamine (TEOA). Through studying the electron-donating effects of two hydroxyl groups introduced into the bipyridyl ligand, we found that the substituent positions greatly affect both the catalytic efficiency and selectivity in CO2 reduction. More importantly, the HCOOH selectivity shows a dramatic increase from 14 to 83% upon switching the solvent media from pure organic to an aqueous/organic mixture, where the H2 selectivity shows a reverse phenomenon. The enhanced HCOOH selectivity and the drastic decrease in the H2 yield are well rationalized by the fact that the catalytic CO2 hydrogenation is not only driven photochemically via the attack of RhIII(H)Cp*(LH2-·) on CO2 but also partly bypassed by a dark H2 addition reaction yielding [RhIII(H)Cp*(L)]- from [RhIIICp*(L)Cl]+, which was also separately investigated under dark conditions. A combination of experimental and theoretical approaches was made to clarify the pKa values of catalyst intermediates together with the abundant species responsible for the major catalytic processes. Our DFT studies unveil that the exceptionally large structural strain given by the steric contacts between the 6,6'-dihydroxyl groups and the Cp* moiety plays a significant role in bringing about an outstanding catalytic performance of the 6,6'-substituted derivative. The intrinsic reaction coordinate calculations were carried out to clarify the mechanism of hydride transfer steps leading to generating formate together with the heterolytic H2 cleavage steps leading to afford the key hydridorhodium intermediates. This study represents the first report on the water-induced high selectivity in CO2-to-HCOOH conversion, shedding new light on the strategy to control the efficiency and selectivity in the catalysis of CO2 reduction.

Dual Active Sites with Charge‐asymmetry in Organic Semiconductors Promoting C−C Coupling for Highly Efficient CO2 Photoreduction to Ethanol

AbstractSelective CO2 photoreduction into high‐energy‐density and high‐value‐added C2 products is an ideal strategy to achieve carbon neutrality and energy shortage, but it is still highly challenging due to the large energy barrier of the C−C coupling step and severe exciton annihilation in photocatalysts. Herein, strong and localized charge polarization is successfully induced on the surface of melon‐based organic semiconductors by creating dual active sites with a large charge asymmetry. Confirmed by multiscale characterization and theoretical simulations, such asymmetric charge distribution, originated from the oxygen dopants and nitrogen vacancies over melon‐based organic semiconductors, reduces exciton binding energy and boosts exciton dissociation. The as‐formed charge polarization sites not only donate electrons to CO2 molecules but also accelerate the coupling of asymmetric *CO*CO intermediates for CO2 photoreduction into ethanol by lowering the energy barrier of this process. Consequently, an exceptionally high selectivity of up to 97 % for C2H5OH and C2H5OH yield of 0.80 mmol g−1 h−1 have been achieved on this dual active sites organic semiconductor. This work, with its potential applicability to a variety of non‐metal multi‐site catalysts, represents a versatile strategy for the development of advanced catalysts tailored for CO2 photoreduction reactions.

Sensitive detection of gallic acid in food by electrochemical sensor fabricated by integrating nanochannel film with nanocarbon nanocomposite

Sensitive detection of gallic acid (GA) in foods is of great significance for assessing the antioxidant properties of products and ensuring consumer health. In this work, a simple electrochemical sensor was conveniently fabricated by integrating vertically-ordered mesoporous silica film (VMSF) with electrochemically reduced graphene oxide (ErGO) and nitrogen graphene quantum dots (NGQDs) nanocomposite, enabling sensitive detection of GA in food sample. A water-soluble mixture of graphene oxide (GO) and NGQDs was drop-cast onto the common carbon electrode, glassy carbon electrode (GCE), followed by rapid growth of VMSF using an electrochemically assisted self-assembly method (EASA). The negative voltage applied during VMSF growth facilitated the in situ reduction of GO to ErGO. The synergistic effects of ErGO, NGQDs, and the nanochannels of VMSF led to nearly a tenfold enhancement of the GA signal compared to that obtained on electrodes modified with either ErGO or NGQDs alone. Sensitive detection of GA was realized with a linear concentration range from 0.1 to 10 μM, and from 10 to 100 μM. The limit of detection (LOD), determined based on a signal-to-noise ratio of three (S/N = 3), was found to be 81 nM. Combined with the size-exclusion property of VMSF, the fabricated sensor demonstrated high selectivity, making it suitable for the sensitive electrochemical detection of gallic acid in food samples.

Silver Electrodes Are Highly Selective for CO in CO2 Electroreduction due to Interplay between Voltage Dependent Kinetics and Thermodynamics.

Electrochemical reduction is a promising way to make use of CO2 as feedstock for generating renewable fuel and valuable chemicals. Several metals can be used as the electrocatalyst to generate CO and formic acid, but hydrogen formation is an unwanted side reaction that can even be dominant. The lack of selectivity is, in general, a significant problem, but silver-based electrocatalysts have been shown to be highly selective, with faradaic efficiency of CO production exceeding 90%, when the applied voltage is below -1 V vs RHE. In this voltage range, only a small amount of hydrogen and formate is formed. We present calculations of the activation free energy for the various elementary steps as a function of applied voltage at the three low index facets, Ag(111), Ag(100) and Ag(110), as well as experimental measurements on polycrystalline electrodes, to identify the reason for this high selectivity. The formation of formic acid is suppressed, even though it is thermodynamically favored, because of the low coverage of adsorbed hydrogen and kinetic hindrance to the formation of the HCOO* intermediate, while *COOH, a key intermediate in CO formation, is thermodynamically unstable until the applied voltage reaches -1 V vs RHE, at which point the kinetics for its formation are more favorable than for hydrogen. The calculated results are consistent with experimental measurements carried out for acidic conditions and provide an atomic scale insight into the high CO selectivity of silver-based electrocatalysts.

Harnessing curcumin and nanotechnology for enhanced treatment of breast cancer bone metastasis.

Breast cancer (BC) bone metastasis poses a significant clinical challenge due to its impact on patient prognosis and quality of life. Curcumin (CUR), a natural polyphenol compound found in turmeric, has shown potential in cancer therapy due to its anti-inflammatory, antioxidant, and anticancer properties. However, its metabolic instability and hydrophobicity have hindered its clinical applications, leading to a short plasma half-life, poor absorption, and low bioavailability. To enhance the drug-like properties of CUR, nanotechnology-based delivery strategies have been employed, utilizing polymeric, lipidic, and inorganic nanoparticles (NPs). These approaches have effectively overcome CUR's inherent limitations by enhancing its stability and cellular bioavailability both in vitro and in vivo. Moreover, targeting molecules with high selectivity towards bone metastasized breast cancer cells can be used for site specific delivery of curcumin. Alendronate (ALN), a bone-seeking bisphosphonate, is one such moiety with high selectivity towards bone and thus can be effectively used for targeted delivery of curcumin loaded nanocarriers. This review will detail the process of bone metastasis in BC, elucidate the mechanism of action of CUR, and assess the efficacy of nanotechnology-based strategies for CUR delivery. Specifically, it will focus on how these strategies enhance CUR's stability and improve targeted delivery approaches in the treatment of BC bone metastasis.

Combinatorial Pattern Response of Bioelectronic Nose for the Detection of Real Nerve Agents.

Nerve agents are toxic organophosphorus chemicals and acetylcholinesterase inhibitors that have been used in terrorist acts. Because they exhibit fatal toxic effects in small amounts, technology is required to detect and identify them early. Research for nerve agent detection using structural simulants of real agents may not function properly for real agents depending on the selectivity of the sensor. For practical sensor applications, experiments were conducted using two toxic nerve agents, sarin and VX, which are used in terrorism and attacks. Herein, human olfactory receptors (ORs) were used as sensing materials with high selectivity and sensitivity to target substances. Through molecular dynamic simulations, the interaction results between ORs and target materials were compared, and an OR combination that could distinguish structurally similar target materials was selected. Four types of OR were combined with a graphene/MoS2-based n-type field-effect transistor platform to create a bioelectronic nose that showed remarkable sensitivity and a stable basal current to convert the biological signals of the OR with target substances into electrical signals. This study developed a nerve agent detection technology using multiple OR sensing signals, advocating combinatorial pattern recognition, which is the core of the human olfactory mechanism. The bioelectronic nose effectively distinguishes structurally similar nerve agents using pattern signals.

Inhibition of Kornblum Reaction with Lithium Salts in SN2 Reactions of Sulfonates and a Nucleophile Containing a Pyridine N-Oxide Moiety: Convergent and Selective Synthesis of an MRGPRX2 Antagonist.

A critical step in the development of a convergent synthesis of an MRGPRX2 antagonist (1) was the SN2 reaction with a highly functionalized lactamide electrophile and a unique difluoropiperidine nucleophile containing a pyridine N-oxide moiety. Initial reactions with sulfonate leaving groups exhibited superb stereoselectivity, but yields were very low due to side reactions originated from competitive Kornblum reactions of the pyridine N-oxide and the sulfonates. Markedly improved reaction profiles were achieved by including stoichiometric lithium triflate. NMR data provided insights into how the lithium cation impacted the pyridine N-oxide through coordination and attenuating its nucleophilicity, leading to the inhibition of the undesired Kornblum reactions. Our approach is highly relevant to preservation of the N-oxide, a structural motif known to several marketed products and emerging as an important class in drug discovery in nucleophilic substitutions. Application of this method enabled the production of the target (1 and its HCl salt 1a) up to multikilogram scale with high selectivity and in much improved yield.

Eco-friendly four spectrophotometric approaches for the simultaneous determination of the recently FDA-approved combination, bupivacaine and meloxicam in pharmaceutical dosage forms

In this study, bupivacaine (BUP) and meloxicam (MLX) were simultaneously assayed in their co-formulated ampoules without interference using four affordable, sensitive, and eco-friendly spectrophotometric methods. The assay of MLX at 359.3 nm over the concentration range of 1.0–15.0 µg/mL was accomplished using a direct UV-spectrophotometric method (Method I) without interference from BUP. However, there was a significant overlap between the spectra of BUP and MLX, making it difficult to determine BUP directly from the UV spectrum. Therefore, various UV-based techniques, including second derivative spectrophotometry (Method II), ratio subtraction method (Method III), and absorption factor method (Method IV), were used to determine BUP over the concentration range of 5.0–80.0 µg/mL. The proposed methods could simultaneously determine the studied drugs with a challenging ratio of 33.3:1.0 (BUP: MLX), which increases the importance of the current study. The proposed methods were applied to estimate the studied drugs in commercial ampoules with high % recoveries and low %RSD values. The excellent eco-friendliness of the developed methods was demonstrated using GAPI and AGREE metrics. The developed methods were validated according to ICHQ2(R2) guidelines. The proposed methods can be better suited for the routine analysis of BUP and MLX in their fixed-dose combination with high selectivity.

Nanomaterial-Based Electrochemical Sensors for the Detection of Pharmaceutical Drugs

The rapidly increasing human population has led to new biological and environmental challenges. These challenges, in turn, have contributed to the rapid growth of the pharmaceutical sector. Quality control in pharmaceutical manufacturing and drug delivery necessitates portable, sensitive, precise, and cost-effective devices to monitor patient dosing and assess pharmaceutical hazards. This study highlights the attributes and applications of the current nanomaterial-based sensors for drug detection, emphasizing the potential of these devices to advance the detection of bioactive molecules, thereby promoting human health and environmental protection on a large scale. Electrochemical sensors, in particular, have become invaluable in bioimaging, electrochemical analysis, and drug delivery due to their high specificity, selectivity, and stability across cycles. This review focuses on recent advancements in electrochemical devices for healthcare applications, detailing their production, analytical performance, and clinical uses.