Cell separation using microfluidics has become an effective method to isolate biological contaminants from bodily fluids and cell cultures,such as isolating bacteria contaminants from microalgae cultures and isolating...Cell separation using microfluidics has become an effective method to isolate biological contaminants from bodily fluids and cell cultures,such as isolating bacteria contaminants from microalgae cultures and isolating bacteria contaminants from white blood cells.In this study,bacterial cells were used as a model contaminant in microalgae culture in a passive microfluidics device,which relies on hydrodynamic forces to demonstrate the separation of microalgae from bacteria contaminants in U and W-shaped cross-section spiral microchannel fabricated by defocusing CO_(2) laser ablation.At a flow rate of 0.7 ml/min in the presence of glycine as bacteria chemoattractant,the spiral microfluidics devices with U and W-shaped cross-sections were able to isolate microalgae(Desmodesmus sp.)from bacteria(E.coli)with a high separation efficiency of 92%and 96%respectively.At the same flow rate,in the absence of glycine,the separation efficiency of microalgae for U-and W-shaped cross-sections was 91%and 96%,respectively.It was found that the spiral microchannel device with a W-shaped cross-section with a barrier in the center of the channel showed significantly higher separation efficiency.Spiral microchannel chips with U-or W-shaped cross-sections were easy to fabricate and exhibited high throughput.With these advantages,these devices could be widely applicable to other cell separation applications,such as separating circulating tumor cells from blood.展开更多
Rifaximin(RFX)is a broad-spectrum oral antibiotic with bactericidal actions against Gram-negative and Gram-positive bacteria.In the present work,a sensitive voltammetric assay for the RFX in pharmaceutical formulation...Rifaximin(RFX)is a broad-spectrum oral antibiotic with bactericidal actions against Gram-negative and Gram-positive bacteria.In the present work,a sensitive voltammetric assay for the RFX in pharmaceutical formulations is designed using nanostructured working electrodes.Surface functionalization with manganese dioxide(MnO_(2))/fullerene-C_(60) nanocomposite exhibited the highest electrochemical responses with a sharp oxidation peak at about 336 mV that was obtained using the differential pulse voltammetry(DPV).The cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS)were applied,while the electrode matrix composition including types of nanomaterials,electroanalytical parameters,and pH eff ect were optimized.To that end,using the DPV,high sensitivity was obtained from the linear calibration curve ranged from 0.8 to 31.5μg·mL^(-1) with the correlation coe fficient of 0.99,limit of detection of 0.76μg·mL^(-1) and limit of quantification of 2.31μg·mL^(-1) .Accordingly,the designed approach is off ering a potential applicability towards the RFX determination in pharmaceutical preparations and its quality control.展开更多
The fast and reliable diagnosis of COVID-19 is the foremost priority for promoting public health interventions.Therefore, double-antibody-based immunobiosensor chips were designed, constructed, and exploited for clini...The fast and reliable diagnosis of COVID-19 is the foremost priority for promoting public health interventions.Therefore, double-antibody-based immunobiosensor chips were designed, constructed, and exploited for clinicaldiagnosis. Gold nanoparticles/tungsten oxide/carbon nanotubes (AuNPs/WO3/CNTs) were used as the active workingsensor surface to support the chemical immobilization of a mixture of SARS-CoV-2 antibodies (anti-RBD-S and anti-RBD-S-anti-Llama monoclonal antibodies). The morphology and chemical functionalization of the fabricateddisposable immunochips was characterized using scanning electron microscopy (SEM), Fourier transform infrared(FTIR) spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). After full assayoptimization, the immunobiosensor showed a high sensitivity to detect SARS-CoV-2-S protein with limits of detectionand quantification of 1.8 and 5.6 pg/mL, respectively. On the other hand, for the SARS-CoV-2 whole virus particleanalysis, the detection and quantification limits were determined to be 5.7 and 17 pg/mL, respectively. The biosensorshowed a highly selective response toward SARS-CoV-2, even in the presence of influenza, nontargeting humancoronaviruses, and Middle East respiratory syndrome coronavirus (MERS-CoV). The immunochips exhibited distinctresponses toward the variants of concern: B.1>C.36.3>Omicron> Delta> Alpha coronavirus variants. For biosensorvalidation, twenty-nine clinical specimens were analyzed, and the impedimetric responses were positively detected fortwo Delta samples, eighteen Omicron samples, and six B.1-type samples in addition to three negative samples.Eventually, the immunobiosensor was fabricated in the form of ready-to-use chips capable of sensitive detection ofvirus variants, especially variants of concern (VOC) and interest, in a specimen within 15 min. The chips providedinstantaneous detection with the direct application of clinical samples and are considered a point-of-care device thatcould be used in public places and hot spots.展开更多
文摘Cell separation using microfluidics has become an effective method to isolate biological contaminants from bodily fluids and cell cultures,such as isolating bacteria contaminants from microalgae cultures and isolating bacteria contaminants from white blood cells.In this study,bacterial cells were used as a model contaminant in microalgae culture in a passive microfluidics device,which relies on hydrodynamic forces to demonstrate the separation of microalgae from bacteria contaminants in U and W-shaped cross-section spiral microchannel fabricated by defocusing CO_(2) laser ablation.At a flow rate of 0.7 ml/min in the presence of glycine as bacteria chemoattractant,the spiral microfluidics devices with U and W-shaped cross-sections were able to isolate microalgae(Desmodesmus sp.)from bacteria(E.coli)with a high separation efficiency of 92%and 96%respectively.At the same flow rate,in the absence of glycine,the separation efficiency of microalgae for U-and W-shaped cross-sections was 91%and 96%,respectively.It was found that the spiral microchannel device with a W-shaped cross-section with a barrier in the center of the channel showed significantly higher separation efficiency.Spiral microchannel chips with U-or W-shaped cross-sections were easy to fabricate and exhibited high throughput.With these advantages,these devices could be widely applicable to other cell separation applications,such as separating circulating tumor cells from blood.
基金the great gratitude to the project fund received from the National Research Centre(NRC,Cairo,Egypt)for the internal grant(No.11090306)。
文摘Rifaximin(RFX)is a broad-spectrum oral antibiotic with bactericidal actions against Gram-negative and Gram-positive bacteria.In the present work,a sensitive voltammetric assay for the RFX in pharmaceutical formulations is designed using nanostructured working electrodes.Surface functionalization with manganese dioxide(MnO_(2))/fullerene-C_(60) nanocomposite exhibited the highest electrochemical responses with a sharp oxidation peak at about 336 mV that was obtained using the differential pulse voltammetry(DPV).The cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS)were applied,while the electrode matrix composition including types of nanomaterials,electroanalytical parameters,and pH eff ect were optimized.To that end,using the DPV,high sensitivity was obtained from the linear calibration curve ranged from 0.8 to 31.5μg·mL^(-1) with the correlation coe fficient of 0.99,limit of detection of 0.76μg·mL^(-1) and limit of quantification of 2.31μg·mL^(-1) .Accordingly,the designed approach is off ering a potential applicability towards the RFX determination in pharmaceutical preparations and its quality control.
基金Open access funding provided by The Science,Technology&Innovation Funding Authority(STDF)in cooperation with The Egyptian Knowledge Bank(EKB).
文摘The fast and reliable diagnosis of COVID-19 is the foremost priority for promoting public health interventions.Therefore, double-antibody-based immunobiosensor chips were designed, constructed, and exploited for clinicaldiagnosis. Gold nanoparticles/tungsten oxide/carbon nanotubes (AuNPs/WO3/CNTs) were used as the active workingsensor surface to support the chemical immobilization of a mixture of SARS-CoV-2 antibodies (anti-RBD-S and anti-RBD-S-anti-Llama monoclonal antibodies). The morphology and chemical functionalization of the fabricateddisposable immunochips was characterized using scanning electron microscopy (SEM), Fourier transform infrared(FTIR) spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). After full assayoptimization, the immunobiosensor showed a high sensitivity to detect SARS-CoV-2-S protein with limits of detectionand quantification of 1.8 and 5.6 pg/mL, respectively. On the other hand, for the SARS-CoV-2 whole virus particleanalysis, the detection and quantification limits were determined to be 5.7 and 17 pg/mL, respectively. The biosensorshowed a highly selective response toward SARS-CoV-2, even in the presence of influenza, nontargeting humancoronaviruses, and Middle East respiratory syndrome coronavirus (MERS-CoV). The immunochips exhibited distinctresponses toward the variants of concern: B.1>C.36.3>Omicron> Delta> Alpha coronavirus variants. For biosensorvalidation, twenty-nine clinical specimens were analyzed, and the impedimetric responses were positively detected fortwo Delta samples, eighteen Omicron samples, and six B.1-type samples in addition to three negative samples.Eventually, the immunobiosensor was fabricated in the form of ready-to-use chips capable of sensitive detection ofvirus variants, especially variants of concern (VOC) and interest, in a specimen within 15 min. The chips providedinstantaneous detection with the direct application of clinical samples and are considered a point-of-care device thatcould be used in public places and hot spots.
