Relative Standard Deviation Values Research Articles

Preparation and characterization of AChE immobilized magnetic bio-nanocomposites (Fe3O4@Cht/Au) for pesticide detection

Free enzymes cause difficulties in many applications due to their insufficient stability, loss of activity in a short time, and most importantly, although they are costly, they are used only once in reactions, lose their effect and cannot be recovered from the environment. Magnetic nanoparticles coated with biocompatible polymeric material are potential candidates for promising enzyme carriers due to their multifunctional pore surfaces, easy removal from the environment provided by the magnetization, ability to main stability under various harsh conditions. This study prepared a biosensor candidate based on the inhibiting acetylcholinesterase enzyme by organophosphate pesticides from chitosan-coated magnetic nanoparticles doped with gold. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction diffractometry, and Fourier transform infrared spectroscopy analysis confirmed the structure of synthesized nanocomposites. Magnetic characteristics of the nanocomposites were assessed using VSM. Bio-nanocomposite (Fe3O4@Cht/Au/AChE) was used to determine environmental pollutants qualitatively. Remediation of organophosphate-containing wastewater is an essential issue for environmental sustainability. In this work, Dichlorvos and Chlorpyrifos were selected as organic pollutants to assess the enzymatic activity of immobilized Fe3O4@Cht/Au/AChE. Optimum conditions for AChE enzyme were immobilized nanostructures (Fe3O4@Cht/Au/AChE) were determined. The optimum pH for the immobilized enzyme was found to be 8, and the optimum temperature was found to be 60 °C. Retained immobilized enzyme activity is found to be around 50% for the 20th reuse. In the presence of 150 µL pesticide, retained immobilized enzyme activity is found to be around 25%. Method validation was performed for pesticides. When using immobilized AChE, the LOD (limit of detection)-LOQ (limit of quantitation) values for Dichlorovos and Chlorpyrifos was obtained in the range of 0.0087–0.029 nM and 0.0014–0.0046 nM, respectively. The relative standard deviation (RSD%) values, which are indicators of precision, were found to be below 2%.

A validated ultra-performance liquid chromatography with tandem mass spectrometry method for the quantification of Brazilian green propolis main compounds

Brazilian green propolis is used in folk medicine because of its various biological properties. The hydroalcoholic extract of Brazilian green propolis is characteristic for possessing several pharmacological properties. Phytochemical investigations have attributed some of these properties to the presence of compounds, which were chosen as analytical markers. This paper reports the development and analytical validation using UPLC-MS/MS in MRM mode. Veratraldehyde was used as an internal standard in qualitative and quantitative analyses of the extracts. Relative standard deviation values obtained for intra-day and inter-day precision were lower than 4%. Of the five parameters for robustness, wavelength detection and flow rate were the critical ones. Limits of detection and quantification ranged from 0.300 to 39.500 ng.mL−1 and from 1.400 to 85.00 ng.mL−1, respectively. The recoveries were between 94.00 and 119.00%, with relative standard deviation values around 5.0%. The developed method is precise, sensitive, and reliable for analysing Brazilian green propolis.

Development and validation of HPLC-ultraviolet method for quantitative determination of pritelivir in human placental perfusion medium.

A simple and reliable HPLC-ultraviolet (HPLC-UV) method was developed and validated for the quantification of pritelivir in the samples of medium from the experiments utilizing the ex vivo technique of dual perfusion of the human placental lobule. Phenacetin was used as an internal standard (IS) in our HPLC-UV method. Chromatographic separation of pritelivir and phenacetin was achieved on a Waters Symmetry C18 HPLC column (100 × 2.1 mm, 3.5 μm) at ambient temperature (22-25°C). The mobile phase was composed of 50% methanol in deionized water (v/v), the flow rate for isocratic elution was established at 0.25 mL/min, and the detection wavelength for pritelivir and IS was set at 254 nm. Pritelivir and IS were extracted with the protein precipitation method using methanol as a solvent. The calibration curve for pritelivir exhibited linearity (r2 > 0.99) within the concentration range from 0.155 to 6.62 μg/mL. Within- and between-day accuracy ranged from 97% to 110% with relative standard deviation (RSD) values not exceeding 10%. The extraction recovery of pritelivir and IS ranged from 89% to 91% with RSD not exceeding 7%. Pritelivir was stable under the storage and sample handling conditions. This validated HPLC-UV method was utilized to quantify pritelivir in the placental perfusion medium samples, and the resulting concentrations were authenticated with incurred sample reanalysis to confirm the reliability of the method.

Electrochemical Immunoassay Platform for Human Monkeypox Virus Detection.

In this study, we reported a selective impedimetric biosensor for the detection of A29 which is the target protein of the monkeypox virus (MPXV). The working principle of the biosensor relies on the interaction mechanism between A29, which is an internal membrane protein of MPXV, and the heparan sulfate receptor. For this purpose, after immobilizing heparan sulfate onto the gold screen-printed electrode surface, its interaction with A29 protein was monitored using electrochemical impedance spectroscopy. After the optimization of experimental parameters, the analytical characteristics of the developed MPVX immunosensor were examined. The developed immunosensor exhibited a linear detection range between 2.0 and 50 ng mL-1, with a detection limit of 2.08 ng mL-1 and a quantification limit of 6.28 ng mL-1. Furthermore, a relative standard deviation value of 2.82% was determined for 25 ng mL-1. Apart from that, sample application studies were also performed with the standard addition of A29 protein to 1:10 diluted real serum samples that were taken from healthy individuals, and very good recovery values were obtained.

DEVELOPMENT AND VALIDATION OF A SIMPLE AND COST-EFFECTIVE UV SPECTROPHOTOMETRIC METHOD FOR QUANTIFYING LINEZOLID

Objective: This study focuses on the development and validation of a sensitive, simple, accurate, precise and cost-effective Ultraviolet-Visible (UV) spectrophotometric method for the quantification of Linezolid, a widely used antibiotic in pharmaceutical formulations. Methods: The analysis utilized a solvent system comprising 80% water and 20% methanol (v/v). The absorbance of standard solutions was measured and a calibration curve was constructed. Various analytical performance parameters, including linearity, range, precision, accuracy, Limit of Detection (LOD), Limit of Quantification (LOQ) and ruggedness, were determined following the International Conference on Harmonization (ICH) Q2 (R1) guidelines. Results: The maximum absorption peak (λmax) of Linezolid was determined to be 251 nm in the selected medium. Beer-Lambert’s law was valid in the concentration range of 0.5–9 μg/ml, with a high correlation coefficient (R2) of 0.9955. The proposed method exhibited a recovery ranging from 99.08 to 100.37% with % Relative Standard Deviation (RSD) value consistently below 2%. Conclusion: The study findings confirm the accuracy, precision and reproducibility of the developed method. Additionally, it is characterized by its simplicity, affordability, and time efficiency. Thus, this method can be effectively employed for the quantification of Linezolid in lipid nanoparticles.

Graphene oxide-based stationary phase synthesis and separation of drug molecules for liquid chromatography (HPLC) analysis

A new graphene oxide-based liquid chromatography stationary phase was synthesized, characterized, and used for the first time in the separation of paracetamol and caffeine in pharmaceutical preparations under reversed phase conditions. For this purpose, graphene oxide was synthesized using the modified Hummers method, and Si-GO stationary phase was obtained by immobilizing graphene oxide on aminopropyl silica. The obtained graphene oxide, Si–GO and aminopropyl silica materials were characterized by XRD, SEM, TEM and FTIR analysis. Different mobile phases were used to separate drug molecules in order to determine the mechanism of interaction between drug molecules and the stationary phase. Once the appropriate solvent system was determined, optimum chromatographic parameters such as mobile phase composition (methanol percentage in water), flow rate and column temperature were determined. The linearity of the method was in the range of 0.989–0.997. The maximum relative standard deviation (% RSD) value was calculated as 0.54. Mean recoveries for paracetamol and caffeine were 98%–99%, respectively, and LOD and LOQ were 6 × 10−3 to 6.5 × 10−3 mg/L and 2 × 10−2 to 2.2 × 10−2 mg/L, respectively. The results showed that the new graphene oxide-based stationary phase could be used for the separation of paracetamol and caffeine in pharmaceutical preparations.

Development and validation of a UV spectrophotometric method for biowaiver studies in pyrazinamide tablets

Development and validation of a UV spectrophotometric method for biowaiver studies in pyrazinamide tablets

Preconcentration of Cu2+, Cr3+, Co2+, and Ni2+ by Solid-Phase Extraction Using a Recently Developed Mixed-Mode Sorbent

The enrichment and simultaneous analysis of Cu2+, Cr3+, Co2+, and Ni2+ by solid-phase extraction method were performed using a stationary phase containing amide functional groups, an aromatic benzene ring, and aliphatic groups in a silica-based structure that we had synthesized for HPLC separations in our previous studies. Solid-phase extraction was performed using a column system and the results obtained were analysed by ICP-OES. Effects of pH, amount of sorbent, amount of eluting solvent, sample volume, flow rates of the eluent and the sample, and interfering ions were evaluated in recovery processes for the metals in the sample solutions. Linear range, detection limit, and relative standard deviation (% RSD) values were calculated for each metal. The linear range (ng/mL) was between 0.01 and 0.25 for all ions, while the limit of detection (ng/mL) was found to be 0.64, 1.7, 0.44, and 0.51 and % RSD was 2.8, 2.4, 2.6, and 2.9 for Cu2+, Cr3+, Co2+, ve Ni2+, respectively.

In situ fabrication of Ag nanoparticles modified vertically-grown ZnO nanorods on carbon fiber paper electrode for simultaneous detection of luteolin, daidzein and baicalein

In this paper, a facial strategy is employed to directly growing ZnO nanorods (ZnONR) on carbon fiber paper (CFP) and functionalizing with silver nanoparticles (AgNP), constructing a structural stable paper-based electrode (AgNP/ZnONR@CFP). This unique AgNP/ZnONR hierarchical nanoarchitecture provides large surface area and an easy substrate penetrable structure facilitating enhanced electrochemical features towards flavonoids oxidation. When the electrode is evaluated as a binder-free sensor for flavonoids detection, three distinct and separate differential pulse voltammetric peaks for luteolin, daidzein, and baicalein are observed, demonstrating the simultaneous and selective detection of these flavonoids possible. The AgNP/ZnONR@CFP sensor demonstrates a remarkable wide linear relationship with low detection limits for luteolin, daidzein, and baicalein detection in a mixed solution. When the sensor is employed to analyze luteolin, daidzein, or baicalein in real extracts from Japanese Honeysuckle, Soybean, and Chrysanthemum morifolium, satisfactory recovery rates (ranging from 96.3 % to 102.5 %) and low relative standard deviation (RSD) values (less than 5.0 %) are obtained. In addition, an assembled sensor device (two-electrode) based on this trimmable AgNP/ZnONR@CFP electrode exhibits remarkable quick response and excellent sensitivity for luteolin, daidzein, or baicalein detection, facilitating real-time and portable detection, highlighting its great potential in batch production of the sensor devices.

Phosphate and Nitrate Electrochemical Sensor Based on a Bifunctional Boron-Doped Diamond Electrode.

Phosphorus and nitrogen are important elements in both environmental cycles and biological growth, and their imbalance can lead to serious environmental and biological problems. It is important to be able to monitor the concentration of nitrate and phosphate in the water online. In this paper, a bifunctional boron-doped diamond (BDD) electrode with repeatable electrochemical renewal and modification ability has been developed and used as a shared working electrode for the determination of nitrate and phosphate. First, phosphate can be detected directly with a bare BDD electrode. After a thin copper (Cu) layer was electrodeposited on the BDD electrode, nitrate could be determined. The copper layer is then removed under a positive voltage, and the BDD electrode is renewed and can be used again for phosphate detection. This method enables the detection of both phosphate and nitrate while also improving the stability and repeatability through the renewal of the electrode surface. The segmented linear ranges for phosphate were 0.02-0.4 and 0.4-3 mg/L with a detection limit of 0.004 mg/L. The sensor detected nitrate in a wide concentration range, with segmented linear relationships in the ranges of 0.07-3 and 3-100 mg/L, with a detection limit of 0.065 mg/L. The electrochemical sensor based on the BDD electrode has a good reproducibility for phosphate and nitrate detection. The relative standard deviation (RSD) values of the current responses were 2.98, 2.79, 1.66, 1.81, and 1.23%, respectively, for 35 consecutive tests in 0.05, 0.2, 0.5, 1, and 1.5 mg/L phosphate solution. The RSD values of the current responses were 2.00, 0.97, and 1.03%, respectively, for 25 consecutive tests in 5, 7, and 10 mg/L nitrate solution.

Hierarchical PVDF/ZnO/Ag/ZIF-8 nanofiber membrane used in trace-level Raman detection of H2S

surface enhanced Raman scattering (SERS) detection of gases has always been difficult due to the low affinity and poor Raman cross section of the moving molecules. To mitigate the impact of these problems on detection of gases, a structure of zinc oxide/silver nanowires coated with zeolitic imidazolate framework-8 (ZnO NWs/Ag/ZIF-8) was constructed on polyvinylidene fluoride (PVDF) nanofiber membrane (PVDF/ZnO NWs/Ag/ZIF-8) and in detail researched in this work. Benefitting from the quadruple synergistic effect of efficient Knudsen diffusion of gas molecules inside ZIF-8, enrichment of ZIF-8 microsponges for gaseous molecules, regulation of ZIF-8 dielectric layer for light and reverse light scattering of ZnO NW/Ag tip, the structure was proven to have precise co-confinement on both hot spots and gaseous molecules. As a result, this PVDF/ZnO NWs/Ag/ZIF-8 achieved excellent detection for hydrogen sulfide (H2S), with a limit of detection of 1 × 10−10 v/v and the minimum relative standard deviation value of ca. 7.13 %. Furthermore, as a proof of concept, in practical application, we designed and assembled our substrate (3.5 cm × 3.5 cm) into a SERS face mask and realized efficient monitoring of H2S in human’s exhaled breath.

In-situ acetylation followed by liquid-liquid extraction and gas chromatography – mass spectrometry for the determination of bromophenols in urine

A novel and simple method combining in-situ acetylation, liquid-liquid extraction and gas chromatography-mass spectrometry (GC-MS) has been developed for the quantification of 10 bromophenols in urine, used as biomarkers of exposure to polybrominated diphenyl ethers. The analytical process involves an enzymatic hydrolysis of the bromophenol glucuronide fraction followed by an aqueous derivatization of the phenol group with acetic anhydride. A subsequent liquid-liquid extraction of the sample with hexane allows the injection of the organic layer, using a programmed temperature vaporizer, into a gas chromatograph coupled to a single quadrupole mass spectrometer. Quantification is performed by the standard addition method. Limits of detection are in the pg mL−1 range. Trueness, assessed in terms of percentages of recovery, varies between 100 % and 118 % in synthetic urine and between 79 % and 117 % in human urine. Precision, assessed at two different levels, 0.25 ng mL−1 and 2.5 ng mL−1, shows values of relative standard deviation below 14 % both in intra- and inter-day studies for both matrices. The method has been applied to the analysis of seven urine samples, measuring concentrations higher than the LOQ in three of them. These levels are in agreement with others found in literature, but they have been obtained by applying a much simpler and faster protocol. In addition, the replacement of silylating reagents by acetic anhydride, to derivatize the phenol moiety, provides a greener alternative to other GC-MS procedures published up to date.

Response surface experimental design for simultaneous chromatographic determination of two antiviral agents “Favipiravir and Remdesivir” in pharmaceuticals and spiked plasma samples

AbstractThe antiviral agents, Favipiravir (FAV) and Remdesivir (REM), were introduced in the last few years alone or as combination regimen for successful management of the rapidly spreading CORONA virus pandemic. A newly developed rapid and sensitive high performance liquid chromatographic method (HPLC) has been developed for the simultaneous determination of their mixture. Firstly, one factor at a time optimization (OFAT) has been applied. Afterwards, quality by design approach (QbD) has been utilized using Box Behnken experimental design (BBD) for the development of an experimental design of four independent and nine dependent variables for much better refining of the optimized parameters. The established model has given an optimum resolution at; acetonitrile percentage of 52.66, mobile phase of pH 2.91, percentage of triethylamine of 0.15 and 1.30 mL/min flow rate. The proposed method has been validated according to the USP 31 NF 26 guidelines. Good linearity ranges have been obtained from 5.00 up to 50.00 μg/mL for FAV and from 2.00 up to 60.00 μg/mL for FAV and REM, respectively. Excellent relative standard deviation values (not more than 1.40) were obtained upon investigation of accuracy, precision and robustness. The developed method has succeeded in analysis of investigated drugs in their pharmaceutical formulations and spiked plasma samples with good recoveries of 99.00 and up to 106.00%. The proposed method is considered eligible for the quality control laboratories as well as in‐vivo determinations of both analytes.

Whole urine-based multiple cancer diagnosis and metabolite profiling using 3D evolutionary gold nanoarchitecture combined with machine learning-assisted SERS

To develop onsite applicable cancer diagnosis technologies, a noninvasive human biofluid detection method with high sensitivity and specificity is required, available for classifying cancer from the normal group. Herein, a three-dimensional evolutionary gold nanoarchitecture (3D-EGN) is developed by forming Au nanosponge (AuS) on a 96-well plate, followed by a decoration of Au nanoparticles (AuNPs) evolved with Au nanolamination (AuNL) for high-throughput urine sensing in liquid phase. The 3D-EGN exhibits not only strong electromagnetic field generated from numerous hotspot regions between AuNPs and further enhanced light scattering from multigrain boundaries after lamination process, but also highly volumetric field due to nanoporous structure of AuS, which is advantageous for sensitive liquid-phase SERS detection. SERS activity of the 3D-EGN platform is characterized using malachite green, showing a limit detection of 1.23 × 10−9 M in liquid phase, and excellent uniformities both within single well and well-to-well with relative standard deviation (RSD) values of about 10%. The 3D-EGN platform has been demonstrated for the detection of whole clinical human urine samples, proving effective molecular sensing in the presence of Brownian motion from liquid medium. Subsequently, cancer metabolite candidates are investigated to verify the metabolic alternations of multicancer, including pancreatic, prostate, lung, and colorectal cancers, simultaneously classifying them into five different groups, including normal with an accuracy of 95.6%, using machine-learning methods. The integration of nanomaterials with the conventional clinical platform provides rapid and high-throughput multicancer diagnostic system and opens a new era for noninvasive diseases diagnosis using clinical human biofluids.

Presence of hazardous chemical elements in low-cost children's toys: A risk to their development in early childhood

ObjectivesThe objectives of the current study was to study the presence of hazardous chemical elements (Ba138, Cd111, Cr52, Pb208, As75, Co59, Cu63, Mn55, Ni60, Se82, Sr88, Zn66 and Hg202) in low-cost children's toys, and the effect of color types on chemical element concentrations. MethodsChildren's toy samples were analyzed using microwave digestion and inductively coupled plasma/mass spectrometry (ICP/MS) method. Samples were prepared into small pieces, and 500 mg of homogenized sample was used for digestion by means of digesting regents HNO3 (65 %, 5 mL) and H2O2 (35 %, 1 mL). During the digestion process, the pressure was held constant at 90 bar and the temperature, hold time, and power were varied 150–170-40° C, 10–30-5 min, 70–90-0 %, respectively. The main operating conditions of ICP/MS were: spray chamber temperature (−20 °C), RF Power (1450 W), nebulizer gas flow (0.9 L/min), auxiliary gas flow (0.8 L/min) and plasma gas flow (14.85 L/min). Samples and blanks were analyzed for 30 s and system was operated in standard mode. ResultsThe excellent method performance was achieved in terms of limit of detection (LOD, 0.001–14.89 µg/L); limit of quantification (LOQ, 0.003–45.12 µg/L); correlation coefficient (R2, 0.975–0.999) with relative standard deviation values (RSD, 0.70–4.98 %). Chemical elements were found in all the toys (0.01–742.72 ng/g) except sample S2 where only Hg202 was found (0.01 ng/g). Outcomes revealed that the Hg202 was present at a very low level (0.01 ng/g) while Zn66 was present at very high level (742.72 ng/g). Furthermore, the toys contamination was also found to be color-specific, with significant amount of chemical elements was found in black type car sample (S5, 946.98 ng/g) whereas other color type samples constitute lower amounts (0.001–210.53 ng/g). Low-cost toys designed for children's use are found to contain chemical elements that should be addressed in the course of action. As a result of exposure to high amounts of chemical elements in toys, children have a high chance of developing cancer.

Machine learning-enhanced drug testing for simultaneous morphine and methadone detection in urinary biofluids

The simultaneous identification of drugs has considerable difficulties due to the intricate interplay of analytes and the interference present in biological matrices. In this study, we introduce an innovative electrochemical sensor that overcomes these hurdles, enabling the precise and simultaneous determination of morphine (MOR), methadone (MET), and uric acid (UA) in urine samples. The sensor harnesses the strategically adapted carbon nanotubes (CNT) modified with graphitic carbon nitride (g-C3N4) nanosheets to ensure exceptional precision and sensitivity for the targeted analytes. Through systematic optimization of pivotal parameters, we attained accurate and quantitative measurements of the analytes within intricate matrices employing the fast Fourier transform (FFT) voltammetry technique. The sensor’s performance was validated using 17 training and 12 test solutions, employing the widely acclaimed machine learning method, partial least squares (PLS), for predictive modeling. The root mean square error of cross-validation (RMSECV) values for morphine, methadone, and uric acid were significantly low, measuring 0.1827 µM, 0.1951 µM, and 0.1584 µM, respectively, with corresponding root mean square error of prediction (RMSEP) values of 0.1925 µM, 0.2035 µM, and 0.1659 µM. These results showcased the robust resiliency and reliability of our predictive model. Our sensor’s efficacy in real urine samples was demonstrated by the narrow range of relative standard deviation (RSD) values, ranging from 3.71 to 5.26%, and recovery percentages from 96 to 106%. This performance underscores the potential of the sensor for practical and clinical applications, offering precise measurements even in complex and variable biological matrices. The successful integration of g-C3N4-CNT nanocomposites and the robust PLS method has driven the evolution of sophisticated electrochemical sensors, initiating a transformative era in drug analysis.

Multiple regional climate model projections to assess building thermal performance in Brazil: Understanding the uncertainty

Understanding the trends and uncertainties in Building Energy Simulation (BES) performance indicators under future climate conditions is crucial for mitigating issues such as overheating and power outages. To address this, we generated a set of weather files for all 27 state capitals in Brazil, considering six climate model projections (three General Circulation Models as driving models and two nested Regional Climate Models) and two distinct emission scenarios from the CORDEX project. We analyzed the variability in climatic variables and subsequently performed BES on a representative Brazilian social housing unit to evaluate its impact on the performance indicators outcomes. Consistent with previous studies, a substantial increase in cooling-related demands was observed in the more pessimistic scenario (RCP8.5) and mild increases in the more optimistic scenario (RCP2.6), with a trend toward stabilization after 2050. Regarding uncertainties, we found higher Relative Standard Deviation (RSD) values for the cooling degree hours indicator. The capitals in the Central-West, Southeast, and South regions exhibited greater uncertainty regarding temperature indicators, whereas the irradiation parameters displayed higher uncertainties in the Northeast region. For the BES outcomes, RSD values as high as 19.9% were found for cooling load values. It was also demonstrated that locations, periods, and scenarios exhibit different extreme climate model projections. Ideally, employing an ensemble of weather files developed from other models would help assess associated uncertainties in the building performance indicators.

Aqueous two-phase system based on hexafluoroisopropanol and acetonitrile for homogeneous liquid-liquid microextraction of cationic dyes


 
 
 
 This work demonstrates that an aqueous two-phase system (ATPS) is formed when a small amount of acetonitrile (ACN) is added to the aqueous hexafluoroisopropanol (HFIP) solution. The effect of ACN amount on the volume of the formed HFIP/ACN phase was investigated. It was also shown that relatively hydrophilic methylene blue was completely extracted into the HFIP/ACN phase whereas its extractability with conventional solvents (hexane, CH2Cl2 and CHCl3) was significantly lower. The obtained results suggest that the HFIP/ACN phase exhibits a relatively high polarity and should be a good choice for the extraction of moderately or even highly polar compounds from aqueous samples. Finally, the developed ATPS was applied for the homogeneous liquidliquid microextraction of four cationic dyes from river water samples prior to HPLC analysis. Under optimised extraction conditions, the enrichment factors were around 150. Calibration curves were linear (R2 ≥ 0.9959) for the concentration level between 0.2–0.5 and 50.0 μg/L and the detection limits were in the range 0.05–0.18 μg/L. The recoveries of the dyes for the spiked water samples were 88.6–98.5%, with the relative standard deviation values less than 9.6%.
 
 
 

Analytical Method Development and Validation of a UV‐Spectrophotometric Technique for Pioglitazone HCL Estimation in Bulk and Polymeric Nanoparticles

AbstractThe type 2 diabetes drug pioglitazone is encapsulated in polymeric (Chitosan/PEG blended PLGA) nanoparticles utilizing solvent evaporation methods. The current research aimed to develop and validate an accessible, accurate, fast, and commercial UV spectrophotometric approach for assessing Pioglitazone in bulk and polymeric nanoparticles. In the estimation method that involves a pH 7.4 phosphate buffer, the maximum absorbance of Pioglitazone is reported to be 269 nm. With a correlation coefficient of 0.999, the drug exhibits linearity in the concentration series of 5–60 µg mL‐1. The proposed technique is validated as per ICH guidelines for linearity, accuracy, precision, and ruggedness. When the proposed technology is used in nano‐formulation, the percent amount of drug estimated to be 99.35% agreed well with the label claim. Recovery experiments at three distinct levels, 50%, 75%, and 100% are used to test the method's accuracy. The recovery rate is estimated to be between 98.91% and 99.11%. The low percent relative standard deviation (RSD) value indicates the method's accuracy and reproducibility. The method's repeatability, intraday, and interday precision are all examined. The approach is precise if the percent RSD value is less than 2. With the assistance of two analysts, the ruggedness of the suggested method is investigated. For the scheduled examination of Pioglitazone in bulk and polymeric nanoparticles, the above process has been developed and validated and proved to be a quick and cost‐effective quality‐control tool in pharmaceuticals.

Frequency shift Raman-based sensing of serum MicroRNA for ultrasensitive cervical cancer diagnosis

Cervical cancer is the most common gynaecological tumor. The development of a sensor for the ultrasensitive detection of cervical cancer is significant in guaranteeing its prognosis. Herein, we proposed a novel surface-enhanced Raman scattering (SERS) analysis platform using a frequency shifts-based sensing model for rapid and ultrasensitive microRNA (miRNA) assay. During the analysis process, miR-21 can be captured by the single-stranded DNA (ssDNA) modified on the platform which is complementary pairing with miR-21. The connection of miR-21 can lead to the variation of the molecular weight and result in the deformation extent of the Raman report molecule 6Thioguanine (6TG); thus, the peak at 1301 cm−1 due to the ring C–N stretches of 6TG shifts to lower frequency. The detection limit (LOD) of the proposed SERS analysis platform is as low as 8.32 aM. Moreover, the platform also has excellent specificity and repeatability, with the relative standard deviation (RSD) value of 6.53 %. Serum samples of cervical cancer patients and healthy subjects were analyzed via the platform and the accuracy of the detection results was verified by qRT-PCR, revealing that SERS results and qRT-PCR results have high homogeneity. Thus, the platform can serve as a potential tool for clinical diagnosis of cervical cancer.