Tricresyl Phosphate Research Articles

Tricresyl phosphate inhibits fertilization in Japanese medaka (Oryzias latipes): Emphasizing metabolic toxicity

As tricresyl phosphate (TCrP) is commonly found in global water sources, its potential reproductive toxicity to fish is of increasing concern. Japanese medaka larvae were exposed to TCrP at 657.9, 1,511, and 4042 ng/L for 100 days. We identified significant fertilization inhibition (6.9%–12.8%) in all exposure groups. Intersex was significantly induced at 4042 ng/L, with an incidence of 22.0%. TCrP exposure also caused dilation of the efferent duct in the testes with maximum duct widths of 83.3, 93.2, and 149.7 μm in the 657.9, 1,511, and 4042 ng/L exposure groups, respectively. These widths were all significantly larger than that observed in the control group (37.7 μm) and likely contributed substantially to fertilization inhibition. The TCrP metabolites 4-OH-MDTP and 3-OH-MDTP, were detected at high concentrations in the liver and elicited 5.8-fold and 5.3-fold greater androgen receptor antagonistic activity than that elicited by TCrP (39.8 μM), which may explain the intersex observed in low exposure groups. 4-OH-MDTP and 3-OH-MDTP elicited anti-estrogenic activities by blocking the estrogen receptor, and the concentrations at which its responses were equal to the IC20 of tamoxifen were 16.1 μM and 18.9 μM, respectively, as detected using the yeast two-hybrid assay. Such anti-estrogenic activities were likely the main driver of dilation of the efferent duct. Observed adverse outcomes after exposure to TCrP all occurred under environmentally relevant concentrations, suggesting considerable ecological risk to wild fish.

Implications of peroxisome proliferator-activated receptor gamma (PPARY) with the intersection of organophosphate flame retardants and diet-induced obesity in adult mice

ABSTRACT Previously, organophosphate flame retardants (OPFRs) were demonstrated to dysregulate homeostatic parameters of energy regulation within an adult mouse model of diet-induced obesity. Using the same OPFR mixture consisting of 1 mg/kg/day of each triphenyl phosphate, tricresyl phosphate, and tris(1,3-dichloro-2-propyl)phosphate, the current study examined the role of peroxisome proliferator-activated receptor gamma (PPARγ) in OPFR-induced disruption by utilizing mice with brain-specific deletion of PPARγ (PPARγKO) fed either a low-fat diet (LFD) or high-fat diet (HFD). Body weight and composition, feeding behavior, glucose and insulin tolerance, circulating peptide hormones, and expression of hypothalamic genes associated with energy homeostasis were recorded. When fed HFD, the effects of OPFR on body weight and feeding behavior observed in the previous wild-type (WT) study were absent in mice lacking neuronal PPARγ. This posits PPARγ as an important target for eliciting OPFR disruption in a diet-induced obesity model. Interestingly, female PPARγKO mice, but not males, experienced many novel OPFR effects not noted in WT mice, including decreased fat mass, altered feeding behavior and efficiency, improved insulin sensitivity, elevated plasma ghrelin and hypothalamic expression of its receptor. Taken together, these data suggest both direct roles for PPARγ in OPFR disruption of obese mice and indirect sensitization of pathways alternative to PPARγ when neuronal expression is deleted.

Occurrence and in vitro toxicity of organic compounds in urban background PM2.5

This study describes the chemical composition and in vitro toxicity of the organic fraction of fine particulate matter (PM2.5) at an urban background site, which receives emissions either from Frankfurt international airport or the city centre, respectively. We analysed the chemical composition of filter extracts (PM2.5) using ultrahigh-performance liquid chromatography coupled to a high-resolution mass spectrometer, followed by a non-target analysis. In parallel, we applied the bulk of the filter extracts to a Microtox and acetylcholinesterase-inhibition assay for in vitro toxicity testing. We find that both the chemical composition and toxicity depend on the prevailing wind directions, and the airport operating condition, respectively. The occurrence of the airport marker compounds tricresyl phosphate and pentaerythritol esters depends on the time of the day, reflecting the night flight ban as well as an airport strike event during November 2019. We compared the organic aerosol composition and toxicity from the airport wind-sector against the city centre wind-sector. We find that urban background aerosol shows a higher baseline toxicity and acetylcholinesterase inhibition compared to rural PM2.5 that is advected over the airport. Our results indicate that the concentration and individual composition of PM2.5 influence the toxicity. Suspected drivers of the acetylcholinesterase inhibition are i.e. organophosphorus esters like triphenyl phosphate and cresyldiphenyl phosphate, and the non-ionic surfactant 4-tert-octylphenol ethoxylate. However, further research is necessary to unambiguously identify harmful organic air pollutants and their sources and quantify concentration levels at which adverse effects in humans and the environment can occur.

Validation of the basic friction equation on Real contact surface based on macro and nano properties of Tribo-film

The formation of tribofilm by lubricant additives plays an important role in improving the performance of boundary lubrication. In previous studies, it has been discussed that the frictional force due to adhesion can be expressed as a product of the real contact area and the shear strength of the contact junction. Therefore, to evaluate the friction mechanism dominated by the tribofilm in detail, it is important to divide and identify the effects of the shear strength and real contact area. However, there are few studies that have verified the relationship between shear strength and macro friction coefficient with experimental data. In this study, nanofrictional property and real contact area of tribofilm was investigated using nanoindentation equipment and contact analysis. The results show that the shear strength of base material and tribofilms are correlated with the macro friction coefficients. In addition, the friction coefficients are calculated by applying the shear strength to the basic friction equation. The result shows that the friction coefficients calculated from the basic friction equation coincide with those measured by the macro friction test at a certain contact ratio of tribofilms formed in Tricresyl phosphate and over based calcium sulfonate.

Modeling the formulation of the PVC cable composition

Increasing the fire-retardant characteristics of polymeric cable materials has attracted the close attention of experts all over the world for many years, since fires are often associated with the ignition of cable products, followed by the spread of fire through cable communications. In this regard, the development of new modern formulations of fireproof compositions with improved performance properties is especially relevant for the production of PVC cable composites. The article describes the production of a new phosphorus-containing flame retardant phenyldixylol phosphate and investigated its physicochemical properties. The new flame retardant was tested in an industrial formulation of a PVC cable composition using dibutoxyethyl adipate as a plasticizer. Using the methods of correlation-regression analysis and optimization, the optimal ratio of the resulting additive and tricresyl phosphate was selected, which provides the best technological and operational parameters of the PVC composite.

Fluorescence Turn-Off Sensing Strategy Based on Al-Based Mof for Selective Detection of Tricresyl Phosphate

Fluorescence Turn-Off Sensing Strategy Based on Al-Based Mof for Selective Detection of Tricresyl Phosphate

Adverse synergies between inhaled carbon monoxide and tricresyl phosphate in aircraft cabin air

Adverse synergies between inhaled carbon monoxide and tricresyl phosphate in aircraft cabin air

Selective Determination of Nicorandil with a Single Planar Solid‐state Potentiometric Ion Selective Electrode

AbstractNovel screen‐printed electrodes (SPEs) were constructed for the quantitation of nicorandil (NIC) in its pharmaceutical formulations. Different ion‐exchangers and plasticizers were investigated, but the optimal potentiometric response was obtained using nicorandil‐phosphotungstate (NIC‐PTA) ion associate and tricresyl phosphate as a plasticizer. A Nernstian response of 58.80±1 mV/decade was obtained over a concentration range of (1×10−6–1×10−2) M with 1×10−5 M as a detection limit. Sensor morphology was characterized using scanning electron microscopy (SEM). The method was validated for the assay of NIC with high selectivity, accuracy (average recovery=100.54 %), and precision (%RSD≤2).

Bioaccumulation of organophosphorus flame retardants in the marine mussel Mytilus galloprovincialis

The bioaccumulation and depuration of seven organophosphorus flame retardants (OPFRs) in marine mussel Mytilus galloprovincialis were studied. OPFRs showed to be bioavailable in aquatic environments. When mussels are exposed to environmentally relevant concentrations of OPFRs, uptake kinetics fit well to a first-order model with a single compartment; in contrast depuration rates were generally underestimated by that model, most likely because it does not take into account the biotransformation of OPFRs by the organisms. The highest bioaccumulation rates were observed for tricresyl phosphate (TCrP), triphenyl phosphate (TPhP) and 2-ethylhexyldiphenylphosphate (EHDPP). This could be due to the presence of aryl groups in these compounds, their low solubility in water, and their affinity for fat tissues. According to these findings TCrP, with a BCF value of 4042 L kg−1 wet weight, should be classified in environmental regulations as an accumulative chemical.

Tri-ortho-cresyl phosphate exposure leads to low egg production and poor eggshell quality via disrupting follicular development and shell gland function in laying hens

Tri-ortho-cresyl phosphate (TOCP) has been used commercially as a plasticizer and a flame retardant, which has been reported to cause multiple toxicities in humans and other animals. However, the effect of TOCP on female reproductive system is still unclear. The aim of this investigation was to evaluate the reproductive toxicity of TOCP in female avian and investigate its molecular mechanism. In the current study, 50 adult hens were given a single oral dose of TOCP (750 mg/kg). Egg laid by the hens were harvested and counted. Egg quality is assessed by determining the shell strength and thickness. Samples of ovary, shell gland, and serum were collected on day 0, 2, 7, and 21 after the administration. The morphological and pathological changes in tissues were examined. Cell death, follicular development, and steroidogenesis were determined to assess the toxicity of TOCP on laying hens. The results showed that egg production, egg weight, and eggshell strength significantly decreased after TOCP exposure. The calcium levels in serum and eggshell decreased and the expression levels of the eggshell formation-related genes calbindin-D28k (CaBP-D28k) and carbonic anhydrase 2 (CA2) were downregulated. The inhibitory effects of TOCP on follicular development and steroidogenesis were observed with changes in the levels of the related proteins such as forkhead box O1 (FoxO1) and mothers against decapentaplegic homolog 2/3 (Smad2/3). Cell death was identified, which might lead to follicular development disorder. Taken together, TOCP reduced the quantity and quality of the eggs laid by the hens through disrupting follicular development, steroidogenesis, and shell gland function.

Improved tribology performances of copper graphite (Cu/C) using a phosphorized oxidization surface obtained with tricresyl phosphate (TCP)

PurposeCopper-graphite (Cu/C) is a type of seal material that has been widely used in liquid rocket engines and with normal metal pairs, has a high wear rate under liquid oxygen lubrication. In this study, bearing steel disks were subjected to a high-temperature oxidization and phosphating progress to create an oxidized tricresyl phosphating film (OTCP) film, using tricresyl phosphate (TCP) as the phosphating solvent. It is hoped that the surface wear rate and friction coefficient can be reduced by this method.Design/methodology/approachThis study aim to form an anti-wear film on the surface of bearing steel, which can significantly improve the lubrication performance of Cu/C and bearing steel. The surfaces of bearing steel disks were dried to remove surface water and then put on a heating plate with a magnetic stirrer and a blue glazed oxide film obtained by heating the disks in the air at 200°C for 1 h. To create the OTCP film, bearing steel disks with a blue glazed oxide film were cleaned ultrasonically three times in ethanol and then placed in baths of TCP. After heating for 2 h at 120°C, excess TCP liquid was removed from the disks using ethanol, leaving an OTCP film on the disk surface.FindingsIt was found that steel coated with an OTCP film demonstrated better tribological performance (lower coefficient of fiction and wear rate) when pairing with Cu/C than either oxidized or untreated bearing steel. Additional chemical reactions occur when the oxide disk is immersed in TCP and the FePO4 film is formed after heating. Additionally, the OTCP film coated steel displayed good corrosion resistance, as confirmed by electrochemical corrosion tests. This finding demonstrates the potential for this process in the aerospace industry.Originality/valueThe preparation of OTCP films via high-temperature oxidization and phosphating of bearing steel was demonstrated, with the tribological properties of the OTCP film being investigated alongside those of the original surface and an oxidized film surface. The fabrication of OTCP films is easily scaled up and exhibits significant advantages as a new technology for applications in mechanical contact seal lubrication.

Hybrid Nanocomposite Based Graphene Sensor for Ultrasensitive Clomipramine HCl Detection

AbstractA potentiometric sensor modified with a nanocomposite of montmorillonite sheets decorated with polyaniline nanofibers (MT‐PANI‐NFs) as an efficient electroactive material and tricresyl phosphate (TCP) as a solvent mediator has been developed for the estimation of clomipramine HCl (CLP.HCl). The optimum potentiometric performance of the sensor was achieved by mixing of MT‐PANI‐NFs : TCP : graphene with a ratio of 2.69 : 30.11 : 67.20 (% wt/wt). The sensor exhibited a Nernstian slope of 59.0±0.1 mV decade−1 over the concentration range of 1.0×10−5−1.0×10−2 mol L−1 with a theoretically calculated detection limit of 5.0×10−6 mol L−1. The sensor performance was scrutinized in terms of several factors including thermal stability, pH effect, response time and selectivity. As, it displayed a high thermal stability at various temperature degrees (10–60 °C) with pH independency in the range of 3.5–8.5. Additionally, the developed sensor exhibited a very rapid performance for CLP.HCl detection with a fast response time of 4 s and reflecting a superior selectivity towards CLP.HCl over the other interfering species. SEM (scanning electron microscope) was used as a characteristic tool for the investigation of the proposed graphene sensor surface. Furthermore, the graphene sensor has been efficiently used for CLP.HCl estimation in its pharmaceutical formulations.

Exploitation of 2D Cu-MOF nanosheets as a unique electroactive material for ultrasensitive Cu(II) ion estimation in various real samples

Herein, hybrid carbon sensor has been developed with graphite sheets as a matrix, tricresyl phosphate (TCP) as a plasticizer and nanosheets of 2D Cu-MOF (metal-organic framework) as an electroactive material for the ultrasensitive Cu(II) ion detection in various real samples. Where, the present study proves the efficiency of 2D Cu-MOF as a promising sensing material for the development of Cu(II) ion selective carbon sensor. The developed 2D Cu-MOF nanosheets based sensor containing 2D Cu-MOF: TCP: graphite in the ratio of 2.67: 30.54: 66.79 (% wt/wt) displayed unique Nernstian behavior over two linearity ranges of 1.0 × 10−11-1.0 × 10−9 and 1.0 × 10−5-1.0 × 10−1 mol L−1 with slopes of 29.5 ± 0.25 and 29.6 ± 0.13 mV decade−1, respectively. The fabricated carbon sensor achieved a widely pH independency, fast response time and superior thermal stability with highly selective and ultrasensitive performance. Moreover, It has been efficiently applied for the Cu(II) ion potentiometric estimation in human hair, sesames seeds, two different tea infusions and tap water real samples.

An adverse outcome pathway based in vitro characterization of novel flame retardants-induced hepatic steatosis

A wide range of novel replacement flame retardants (nFRs) is consistently detected in increasing concentrations in the environment and human matrices. Evidence suggests that nFRs exposure may be associated with disruption of the endocrine system, which has been linked with the etiology of various metabolic disorders, including nonalcoholic fatty liver disease (NAFLD). NAFLD is a multifactorial disease characterized by the uncontrolled accumulation of fats (lipids) in the hepatocytes and involves multiple-hit pathogenesis, including exposure to occupational and environmental chemicals such as organophosphate flame retardants (OPFRs). In the present study we aimed to investigate the potential mechanisms of the nFRs-induced hepatic steatosis in the human liver cells. In this study, we employed an in vitro bioassay toolbox to assess the key events (KEs) in the proposed adverse outcome pathways (AOP) (s) for hepatic steatosis. We examined nine nFRs using AOP- based in vitro assays measuring KEs such as lipid accumulation, mitochondrial dysfunction, gene expression, and in silico approach to identify the putative molecular initiating events (MIEs). Our findings suggest that several tested OPFRs induced lipid accumulation in human liver cell culture. Tricresyl phosphate (TMPP), triphenyl phosphate (TPHP), tris(1,3-dichloropropyl) phosphate (TDCIPP), and 2-ethylhexyl diphenyl phosphate (EHDPP) induced the highest lipid accumulation by altering the expression of genes encoding hepatic de novo lipogenesis and mitochondrial dysfunction depicted by decreased cellular ATP production. Available in vitro data from ToxCast and in silico molecular docking suggests that pregnane X receptor (PXR) and peroxisome proliferator-activated receptor gamma (PPARγ) could be the molecular targets for the tested nFRs. The study identifies several nFRs, such as TMPP and EHDPP, TPHP, and TDCIPP, as potential risk factor for NAFLD and advances our understanding of the mechanisms involved, demonstrating the utility of an AOP-based strategy for screening and prioritizing chemicals and elucidating the molecular mechanisms of toxicity.

PXR-mediated organophorous flame retardant tricresyl phosphate effects on lipid homeostasis

An emerging experimental framework suggests that endocrine-disrupting compounds are candidate obesogens. However, this potential effect has not yet been determined for Tricresyl phosphate (TCP), a mass-produced organophosphate flame retardant (OPFR) that has been exposed to human beings in many ways. Many OPFRs, including TCP, have been shown to activate pregnane X receptor (PXR), a nuclear receptor that regulates lipid metabolism. Accordingly, we found that TCP exposure caused lipid accumulation in HepG2 cells in this study. Therefore, to elucidate the role of PXR played in TCP metabolism and promotion of lipid accumulation, HepG2 cells were exposed to different concentrations (5 × 10−8 to 5 × 10−5 M) of TCP for 24 h. The enlarged hepatic lipid droplets and increased hepatic triglyceride contents were observed in HepG2 cells after TCP exposure for 24 h. This is the result of a confluence of lipogenesis increase and β-oxidation suppression imposed by PXR activation which was verified by the up regulation of genes in fatty acid (FA) synthesis and the down regulation of genes in β-oxidation. Surface plasmon resonance (SPR) analysis and molecular docking revealed favorable binding mode of TCP to PXR and the knockout of PXR gene with CRISPR/cpf1 system in HepG2 cells abolished TCP-induced triglyceride accumulation, thus underlying the crucial role of PXR in hepatic lipid metabolism resulting from OPFRs exposure. This study enhances our understanding of molecular mechanisms and associations of PXR in lipid metabolism disturbance induced by TCP and provides novel evidence regarding the lipotoxicity effect and potential metabolism pathway of OPFRs.

Ultrafast response humidity sensors based on polyvinyl chloride/graphene oxide nanocomposites for intelligent food packaging

Fabricating high response humidity sensors can create new-fashioned applications and avenues for stakeholder interaction. Thus, this paper addresses an efficient fabrication route based on consolidated graphene oxide (GO) nanoplatelets inside the polyvinyl chloride (PVC) in presence tricresyl phosphate (TCP) plasticizer by In-situ method. The structure of synthesized GO was verified by X-ray diffraction (XRD) and Fourier transform infrared imaging microscopic analysis (FT-IR-IM). Three different proportions of GO (i.e., 1, 3 and 6 wt.%) were used to fabricate plasticized PVC sensors. The morphology of sensors was investigated by atomic force microscopy (AFM) and transmission electron microscopy (TEM) techniques. The AFM & TEM images showed that better dispersion of GO nanoplatelets in the PPVC matrix occurred at 1 and 3 wt.%. Furthermore, other measurements such as Raman spectroscopy, mechanical properties and thermogravimetric analysis (TGA) were conducted on the fabricated PVC sensors. Also, the humidity sensing properties were tested in a wide range of relative humidity (11–85 % RH) and frequency (100 Hz–100 kHz). The data manifested that the optimum measuring frequency was 1 kHz. Moreover, the obtained results from humidity sensing at 1 kHz exhibited that sensor 3 (PPVC/GO-3%) possessed higher sensitivity, lower hysteresis with ultrafast response speed (∼ 4 s) and recovery time (∼ 6 s) compared to other sensors. This result reveals excellent possibility of using sensor 3 as humidity sensing for intelligent food packaging and other practical applications.

Characteristics and risk assessment of organophosphate esters and phthalates in soils and vegetation from Dalian, northeast China

We investigated the concentration, composition, and potential risk of organophosphate esters (OPEs) and phthalates (PAEs) in soils and vegetation from rural areas of Dalian, Northeast China. The residues of total OPEs and PAEs in soils were in the range of 33.1–136 ng/g dw (dry weight) and 465–5450 ng/g dw, while the values in plants were 140–2360 ng/g dw and 2440–21800 ng/g dw, respectively. The concentrations of both chemicals in the plant rhizosphere soils were significantly lower than those in the bulk soils, suggesting an enhanced degradation or uptake by plant. The contaminations in soils also varied for different land use types with the concentrations generally higher in paddy soils than those in maize soils. The OPE and PAE concentrations in plant leaves were slightly higher than those in their corresponding roots. The bioconcentration factors of OPEs & PAEs were significantly negatively correlated with their octanol-water partition coefficients. A hazard assessment suggested potential medium to high risks from tricresyl phosphate (TMPP) and di-n-butyl phthalate (DNBP) for the agricultural soils in Dalian of China. Although the ecological risks of OPEs and PAEs in the rhizosphere soils were lower than those in the bulk soils, the relevant risk could still endanger human health via oral intake of these plants. The daily dietary intakes of OPEs and PAEs via vegetable and rice consuming were estimated, and the result suggests a higher exposure risk via ingestion of leafy vegetable than rice.

Patch test results in patients with suspected contact allergy to shoes: Retrospective IVDK data analysis 2009-2018.

Allergic contact dermatitis caused by shoes is common and new relevant allergens have been identified. To investigate the pattern of type IV sensitization in patients with suspected allergic contact dermatitis of the feet related to shoes as a presumed culprit trigger. Retrospective analysis of data of the Information Network of Departments of Dermatology (IVDK), 2009-2018. Six hundred twenty-five patients with presumed shoe dermatitis were identified in a cohort of 119 417 patients. Compared to patients with suspected contact sensitization from other allergen sources (n=118 792), study group patients were more frequently sensitized to potassium dichromate (10.8% vs 3.5%), colophony (7.2% vs 3.7%), mercaptobenzothiazole (MBT; 4.0% vs 0.6%), mercapto mix (4.6% vs 0.6%), and p-tert-butylphenol formaldehyde resin (1.6% vs 0.5%). Sensitizations to urea formaldehyde resin, melamine formaldehyde resin, glutaraldehyde, tricresyl phosphate, and phenyl glycidylether were rare. Moreover, reactions to compounds in the leather or textile dyes test series were scarce. A distinct sensitization pattern was observed in patients with suspected allergy to shoe materials. Although substances with low sensitization rates should be removed from the leather and shoe patch test series, novel potential allergens should be added.

Neurodevelopmental toxicity assessment of flame retardants using a human DNT in vitro testing battery

Due to their neurodevelopmental toxicity, flame retardants (FRs) like polybrominated diphenyl ethers are banned from the market and replaced by alternative FRs, like organophosphorus FRs, that have mostly unknown toxicological profiles. To study their neurodevelopmental toxicity, we evaluated the hazard of several FRs including phased-out polybrominated FRs and organophosphorus FRs: 2,2′,4,4′-tetrabromodiphenylether (BDE-47), 2,2′,4,4′,5-pentabromodiphenylether (BDE-99), tetrabromobisphenol A, triphenyl phosphate, tris(2-butoxyethyl) phosphate and its metabolite bis-(2-butoxyethyl) phosphate, isodecyl diphenyl phosphate, triphenyl isopropylated phosphate, tricresyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tert-butylphenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, tris(1-chloroisopropyl) phosphate, and tris(2-chloroethyl) phosphate. Therefore, we used a human cell–based developmental neurotoxicity (DNT) in vitro battery covering a large variety of neurodevelopmental endpoints. Potency according to the respective most sensitive benchmark concentration (BMC) across the battery ranked from <1 μM (5 FRs), 1<10 μM (7 FRs) to the >10 μM range (3 FRs). Evaluation of the data with the ToxPi tool revealed a distinct ranking (a) than with the BMC and (b) compared to the ToxCast data, suggesting that DNT hazard of these FRs is not well predicted by ToxCast assays. Extrapolating the DNT in vitro battery BMCs to human FR exposure via breast milk suggests low risk for individual compounds. However, it raises a potential concern for real-life mixture exposure, especially when different compounds converge through diverse modes-of-action on common endpoints, like oligodendrocyte differentiation in this study. This case study using FRs suggests that human cell–based DNT in vitro battery is a promising approach for neurodevelopmental hazard assessment and compound prioritization in risk assessment.Graphical abstract

Polyvinyl Chloride Modified Carbon Paste Electrodes for Sensitive Determination of Levofloxacin Drug in Serum, Urine, and Pharmaceutical Formulations.

Levofloxacin (LF) is a medically important antibiotic drug that is used to treat a variety of bacterial infections. In this study, three highly sensitive and selective carbon paste electrodes (CPEs) were fabricated for potentiometric determination of the LF drug: (i) CPEs filled with carbon paste (referred to as CPE); (ii) CPE coated (drop-casted) with ion-selective PVC membrane (referred to as C-CPE); (iii) CPE filled with carbon paste modified with a plasticizer (PVC/cyclohexanone) (referenced as P-CPE). The CPE was formulated from graphite (Gr, 44.0%) and reduced graphene oxide (rGO, 3.0%) as the carbon source, tricresyl phosphate (TCP, 47.0%) as the plasticizer; sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (St-TFPMB, 1.0%) as the ion exchanger; and levofloxacinium-tetraphenylborate (LF-TPB, 5.0%) as the lipophilic ion pair. It showed a sub-Nernstian slope of 49.3 mV decade−1 within the LF concentration range 1.0 × 10−2 M to 1.0 × 10−5 M, with a detection limit of 1.0 × 10−5 M. The PVC coated electrode (C-CPE) showed improved sensitivity (in terms of slope, equal to 50.2 mV decade−1) compared to CPEs. After the incorporation of PVC paste on the modified CPE (P-CPE), the sensitivity increased at 53.5 mV decade−1, indicating such improvement. The selectivity coefficient () against different interfering species (Na+, K+, NH4+, Ca2+, Al3+, Fe3+, Glycine, Glucose, Maltose, Lactose) were significantly improved by one to three orders of magnitudes in the case of C-CPE and P-CPE, compared to CPEs. The modification with the PVC membrane coating significantly improved the response time and solubility of the LF-TPB within the electrode matrix and increased the lifetime. The constructed sensors were successfully applied for LF determination in pharmaceutical preparation (Levoxin® 500 mg), spiked urine, and serum samples with high accuracy and precision.