Progress of antibody-drug conjugates (ADCs) targeting c-Met in cancer therapy; insights from clinical and preclinical studies.

The cell-surface receptor tyrosine kinase c-mesenchymal-epithelial transition factor (c-Met) is overexpressed in a wide range of solid tumors, making it an appropriate target antigen for the development of anticancer therapeutics. Various antitumor c-Met-targeting therapies (including monoclonal antibodies [mAbs] and tyrosine kinases) have been developed for the treatment of c-Met-overexpressing tumors, most of which have so far failed to enter the clinic because of their efficacy and complications. Antibody-drug conjugates (ADCs), a new emerging class of cancer therapeutic agents that harness the target specificity of mAbs to deliver highly potent small molecules to the tumor with the minimal damage to normal cells, could be an attractive therapeutic approach to circumvent these limitations in patients with c-Met-overexpressing tumors. Of great note, there are currently nine c-Met-targeting ADCs being examined in different phases of clinical studies as well as eight preclinical studies for treating various solid tumors. The purpose of this study is to present a broad overview of clinical- and preclinical-stage c-Met-targeting ADCs.

Predictors of antiretroviral treatment failure to the first line therapy: a cross-sectional study among Iranian HIV-positive adults.

BACKGROUND: HIV virological failure is one of the main problems in HIV-infected patients, and identifying the main predictors of such treatment failure may help in combating HIV/AIDS. METHODOLOGY: This cross-sectional study included 1800 HIV-infected patients with either virological failure or treatment response. HIV viral load, CD4 count, and other tests were performed. Statistical analysis was used to determine the predictors of virological failure. RESULTS: Clinical stage, treatment with reverse transcriptase inhibitors (RTIs), under therapy for three years or more, suboptimal adherence to antiretroviral treatment (ART), age > 40 years, CD4 count < 200 cells/mm3, unemployment, being infected through sex, and the presence of symptoms were the predominant risk factors for virological failure. In addition, 55% of patients who experienced virological failure failed to experience immunological and/or clinical failure. CONCLUSION: As the first study in southern Iran and the second in Iran, Iranian policymakers should focus on intensive counseling and adherence support and emphasize more effective treatment regimens such as protease and integrase inhibitors (PIs and INTIs), to increase the chance of a treatment response to ART. The accuracy of identifying clinical and immunological criteria in resource-limited settings is not promising. The present findings can be used to determine effective measures to control HIV treatment failure and design efficient strategies for the ambitious 95-95-95 plan.

Dual Ni/Co-hemin metal-organic framework-PrGO for high-performance asymmetric hybrid supercapacitor.

In this study, we conducted direct synthesis of a dual metal-organic framework (Ni/Co-Hemin MOF) on phosphorous-doped reduced graphene oxide (PrGO) to serve as an active material in high-performance asymmetrical supercapacitors. The nanocomposite was utilized as an active material in supercapacitors, exhibiting a noteworthy specific capacitance of 963 C g-1 at 1.0 A g-1, along with a high rate capability of 68.3% upon increasing the current density by 20 times, and superior cycling stability. Our comprehensive characterization and control experiments indicated that the improved performance can be attributed to the combined effect of the dual MOF and the presence of phosphorous, influencing the battery-type supercapacitor behavior of GO. Additionally, we fabricated an asymmetric hybrid supercapacitor (AHSC) using Ni/Co-Hemin/PrGO/Nickel foam (NF) and activated carbon (AC)/NF. This AHSC demonstrated a specific capacitance of 281 C g-1 at 1.0 A g-1, an operating voltage of 1.80 V, an impressive energy density of 70.3 Wh kg-1 at a high power density of 0.9 kW kg-1. Notably, three AHSC devices connected in series successfully powered a clock for approximately 42 min. These findings highlight the potential application of Hemin-based MOFs in advanced supercapacitor systems.

Changes in incidence and mortality trend due to COVID-19 in southern Iran, from 2020 to 2021: based on Cochran-Armitage trend test.

Background: In 2020, COVID-19 spread rapidly in Iran and other parts of the world. Some of the epidemiological aspects of this disease remain unknown; therefore, the present study was designed with the aim of determining the trend of incidence and mortality of COVID-19 from February 2020 to July 2021 in southern Iran. Methods: The present study was a cross-sectional analytical study that included all people who had COVID-19 in the period from February 2020 to July 2021 and whose information had been registered in the Infectious Diseases Center of Larestan city and MCMC unit. The study area included the cities of Larestan, Evaz, and Khonj, located in the south of Fars province in southern Iran. Results: Since the emergence of COVID-19 until July 2021, a total of 23,246 new cases of infection were reported in the southern region of Fars province. The average age of patients was 39.90±18.30 years and the range of ages varied from 1 to 103 years. The results of the Cochran-Armitage trend test showed that the trend of the disease in 2020 was completely upward. The first positive case of COVID-19 was recorded on February 27, 2020. The incidence curve in 2021 is sinusoidal, but in general, the results of the Cochran-Armitage trend test showed that the incidence of the disease increased significantly (P-trend < 0.001). Most cases were reported in July, April, and the end of March. Conclusion: In general, the incidence rate of COVID-19 has varied sinusoidally from 2020 to mid-2021. Although the incidence of the disease increased, the number of deaths has fallen. It seems that the increase in the number of diagnostic tests and the implementation of the national COVID-19 immunization program have been effective in changing the trend of the disease.

Chemical Sensors Based on Molecularly Imprinted Polymers Can Determine Drug Release Kinetics from Nanocarriers without Filtration, Centrifugation, and Dialysis Steps.

With the development of drug delivery systems, the use of nanomaterials for slow, targeted, and effective drug release has grown significantly. To ensure the quality of performance, it is essential to obtain drug release profiles from therapeutic nanoparticles prior to in vivo testing. Typically, the methods of monitoring the drug release profile from nanoparticle drug delivery systems include one or more filtration, separation, and sampling steps, with or without membrane, which cause several systematic errors and make the process time-consuming. Here, the release rate of doxorubicin as a model drug from liposome as a nanocarrier was determined via highly selective binding of released doxorubicin to the doxorubicin-imprinted electropolymerized polypyrrole as a molecularly imprinted polymer (MIP). Incubation of the MIP-modified substrate with imprinted cavities complementary to doxorubicin molecules in the releasing medium leads to the binding of released doxorubicin molecules to cavities. The drug trapped in the cavities is determined by one of the analytical methods depending on its signaling properties. In this work, due to the favorable electrochemical properties of doxorubicin, the voltammetry method was used for quantitative analysis of released doxorubicin. The voltammetric oxidation peak current intensity of doxorubicin on the surface of the electrode was enhanced by increasing the release time. This membranelle platform allows fast, reliable, and simple monitoring of drug release profiles without any sample preparation, filtration, and centrifugation in buffer and blood serum samples.

Facile synthesis of NiTe2-Co2Te2@rGO nanocomposite for high-performance hybrid supercapacitor.

The design of bimetallic tellurides that exhibit excellent electrochemical properties remains a huge challenge for high-performance supercapacitors. In the present study, tellurium is consolidated on CoNi2@rGO for the first time, to synthesize NiTe2-Co2Te2@rGO nanocomposite by using a facile hydrothermal method. As-prepared NiTe2-Co2Te2@rGO nanocomposite was characterized by EDS, TEM, FESEM, Raman, BET, XRD, and XPS techniques to prove the structural transformation. Upon the electrochemical characterization, NiTe2-Co2Te2@rGO has notably presented numerous active sites and enhanced contact sites with the electrolyte solution during the faradic reaction. The as-prepared nanocomposite reveals a specific capacity of 223.6 mAh g-1 in 1.0 M KOH at 1.0 A g-1. Besides, it could retain 89.3% stability after 3000 consecutive galvanostatic charge-discharge cycles at 1.0 A g-1 current density. The hybrid supercapacitor, fabricated by activated carbon as an anode site, and NiTe2-Co2Te2@rGO as a cathode site, presents a potential window of 1.60 V with an energy density of 51 Wh kg-1 and a power density of 800 W kg-1; this electrode is capable of lighting up two red LED lamps and a yellow LED lamp for 20 min, which is connected in parallel. The present work opens new avenues to design and fabrication of nanocomposite electrode materials in the field of supercapacitors.

Self-healing 2D/3D perovskite for efficient and stable p-i-n perovskite solar cells.

Beyond the p-i-n perovskite solar cell's high-power conversion efficiency (PCE), its moisture instability is the most challenging factor in its commercialization. Recently, the innovative use of three and two-dimensional multi-structures, by creating a barrier against the penetration of moisture and oxygen, has played a very influential role in improving the PSC's long-term stability. Here, a new strategy, the anti-solvent quenching method, is used to construct multi-structure perovskite by involving cetyltrimethylammonium bromide (CTAB) as an active agent. The solar cell efficiency is significantly improved during the perovskite formation on the substrate by creating a multidimensional (2D/3D) heterojunction perovskite. The synergistic role of using 2D/3D heterojunction perovskite structures led to the 29.2% improvement (14.58-18.84) in the PCE. The attractive ability of the 2D/3D active layer in self-healing has increased the perovskite's long-term stability under harsh environmental conditions.

Antisolvent Additive Engineering for Boosting Performance and Stability of Graded Heterojunction Perovskite Solar Cells Using Amide-Functionalized Graphene Quantum Dots.

Additive and antisolvent engineering strategies are outstandingly efficient in enhancing perovskite quality, photovoltaic performance, and stability of perovskite solar cells (PSCs). In this work, an effective approach is applied by coupling the antisolvent mixture and multi-functional additive procedures, which is recognized as antisolvent additive engineering (AAE). The graphene quantum dots functionalized with amide (AGQDs), which consists of carbonyl, amine, and long hydrophobic alkyl chain functional groups, are added to the antisolvent mixture of toluene (T) and hexane (H) as an efficient additive to form the CH3NH3PbI3 (MAPI):AGQDs graded heterojunction structure. A broad range of analytical techniques, including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, space charge limited current, UV-visible spectroscopy, external quantum efficiency, and time-of-flight secondary ion mass spectrometry, are used to investigate the effect of AAE treatment with AGQDs on the quality of perovskite film and performance of the PSCs. Importantly, not only a uniform and dense perovskite film with hydrophobic property is obtained but also defects on the perovskite surface are significantly passivated by the interaction between AGQDs and uncoordinated Pb2+. As a result, an enhanced power conversion efficiency (PCE) of 19.10% is achieved for the champion PSCs treated with AGQD additive, compared to the PCE of 16.00% for untreated reference PSCs. In addition, the high-efficiency PSCs based on AGQDs show high stability and maintain 89% of their initial PCE after 960 h in ambient conditions.

Simultaneous determination of some opioid drugs using Cu-hemin MOF@MWCNTs as an electrochemical sensor.

Due to its toxicological and pharmacological activity, the misuse and overuse of morphine (MO), codeine (CO), and heroine have attracted attention in the medical and forensic toxicology fields. This study proposed a new electrochemical sensor with an acceptable detection limit, linear range, and selectivity for simultaneous determination of MO and CO. This sensor is based on Cu-Hemin metal-organic framework (CHM) and multiwall carbon nanotubes (MWCNTs). First, a facile chemical method was chosen to synthesize CHM and then composite it with MWCNTs. Afterward, the structure of CHM@MWCNTs was verified by XRD, FT-IR, Raman spectroscopy, UV-vis, ICP-OES, FE-SEM, EDX, and elemental mapping. In the next step, under optimal conditions, this electrochemical sensor can sensitive simultaneous determination of MO and CO, showing a dynamic concentration range from 0.09 to 30 µM for both species and a low detection limit of 9.2 nM and 11.2 nM for MO and CO, respectively. Moreover, the applicability in real samples was confirmed by the simultaneous determination of MO and CO in human urine and MO injection. This work reveals a trustable sensor based on MOF and MWCNTs to simultaneously determine opioid drugs in clinical application.

Changing Patterns in Epidemiology of Brucellosis in the South of Iran (2015-2020): Based on Cochrane-Armitage Trend Test.

BACKGROUND: Brucellosis is known in Iran as an endemic disease; however, its incidence is not the same in all provinces and is higher in some areas. OBJECTIVE: The present study was designed to determine the epidemiological status and trend of brucellosis in the period from 2015 to 2020 in the south of Fars province, Southern Iran. METHODS: This is a cross-sectional analytical study. This study included all patients with brucellosis in the period from 2015 to 2020 whose information had been registered in the Infectious Diseases Center of Larestan city. To collect the data, we used a checklist that included information such as age, gender, number of cases by year and month, occupation, and nationality of the patients with brucellosis. The rate of brucellosis incidence during these years was analyzed using the Cochran-Armitage trend test. P-value less than 0.05 was considered significant. RESULTS: The average annual incidence of the disease was 8.94 per 100 000 population. It has decreased from 26.83 (per 100 000 people) in 2015 to 1.83 (per 100 000 people) in 2020. The results of Cochrane-Armitage process test showed that the reduction in the incidence of the disease from 2015 to 2020 was significant (PTrend = 0.001). The trend of the disease by month also showed that the majority of cases occurred between December and February, with the highest incidence of the disease in February (9.93 per 100 000 people) and the lowest in May (1.1 per 100 000 people) (P = 0.001). CONCLUSION: Although the results of the present study indicated a decrease in the incidence of the disease in the southern region of Fars province, due to the fact that the disease is common between humans and livestock, there is the possibility of scattered and irregular epidemics in each period.

Ultrasensitive electrochemical molecularly imprinted sensor based on AuE/Ag-MOF@MC for determination of hemoglobin using response surface methodology.

Considering the importance of determining the levels of hemoglobin (Hb) as a vital protein in red blood cells, in this work a highly sensitive electrochemical sensor was developed based on a gold electrode (AuE) modified with Ag metal-organic framework mesoporous carbon (Ag-MOF@MC) and molecularly imprinted polymers (MIPs). To that end, the MIP layer was formed on the Ag-MOF@MC by implanting Hb as the pattern molecule during the polymerization. The modified electrode was designed using electrochemical approaches including differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Using a response level experimental design method, the most important parameters affecting the reaction of the sensing system including pH, incubation time, and scanning rate were optimized. Following the same route, the Hb concentration, pH, temperature, and elution times were optimized to prepare the imprinted polymer layer on the Ag-MOF@MC surface. By exploiting DPV techniques based on the optimal parameters, the electrochemical response of the AuE/Ag-MOF@MC-MIPs for Hb determination was recorded in a wide linear dynamic range (LDR) of 0.2 pM to 1000 nM, with a limit of detection (LOD) of 0.09 pM. Moreover, the Ag-MOF@MC-MIP sensing system showed good stability, high selectivity, and acceptable reproducibility for Hb determination. The sensing system was successfully applied for Hb determination in real blood samples, and the results were compared with those of the standard methods for Hb determination. Acceptable recovery (99.0%) and RDS% (4.6%) confirmed the applicability and reliability of the designed Hb sensing system.

Induced Pluripotent Stem Cells (iPSCs) Provide a Potentially Unlimited T Cell Source for CAR-T Cell Development and Off-the-Shelf Products.

Chimeric antigen receptor T (CAR-T) cell therapy has been increasingly conducted for cancer patients in clinical settings. Progress in this therapeutic approach is hampered by the lack of a solid manufacturing process, T lymphocytes, and tumor-specific antigens. T cell source used in CAR-T cell therapy is derived predominantly from the patient's own T lymphocytes, which makes this approach impracticable to patients with progressive diseases and T leukemia. The generation of autologous CAR-T cells is time-consuming due to the lack of readily available T lymphocytes and is not applicable for third-party patients. Pluripotent stem cells, such as human induced pluripotent stem cells (hiPSCs), can provide an unlimited T cell source for CAR-T cell development with the potential of generating off-the-shelf T cell products. T-iPSCs (iPSC-derived T cells) are phenotypically defined, expandable, and as functional as physiological T cells. The combination of iPSC and CAR technologies provides an exciting opportunity to oncology and greatly facilitates cell-based therapy for cancer patients. However, T-iPSCs, in combination with CARs, are at the early stage of development and need further pre-clinical and clinical studies. This review will critically discuss the progress made in iPSC-derived T cells and provides a roadmap for the development of CAR iPSC-derived T cells and off-the-shelf T-iPSCs.

Electrochemical sensor based on glassy carbon electrode modified by polymelamine formaldehyde/graphene oxide nanocomposite for ultrasensitive detection of oxycodone.

Polymelamine formaldehyde/graphene oxide (PMF/GO) nanocomposite was used, for the first time, to study the ultrasensitive and selective electrochemical detection of oxycodone (OXC). The successful characterization of PMF/GO was verified based on scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and Raman spectroscopy. The modified GCE (PMF/GO-GCE) proved its electrocatalytic effect on OXC determination according to cyclic, linear sweep, and differential pulse voltammetry (CV, LSV, and DPV) and electrochemical impedance spectroscopy (EIS) studies. The developed sensor under optimal conditions offered a linear relationship in a limited range of  0.01 to 45 µmol L-1 with the limit of detection (LOD) of 2.0 nmol L-1. The proposed PMF/GO-GCE sensor was effectively employed for the OXC detection in human urine and serum samples. Graphical abstract.

Development of an eco-friendly fluorescence nanosensor based on molecularly imprinted polymer on silica-carbon quantum dot for the rapid indoxacarb detection.

Rapid and efficient detection of indoxacarb (IXC), a common chemical contaminant, in environmental and biological samples is necessary. In this work, a modern optical sensor was developed for IXC, based on environmentally friendly molecularly imprinted polymer (MIP) coated on silica-carbon quantum dots (SiCQDs). A hydrothermal method was used to prepare highly fluorescence SiCQDs and, subsequently, MIP formed on surface (MIP@SiCQDs) using a sol-gel method. A linear relationship between the fluorescence quenching effect and increased IXC concentration was found for the range of 4-102 nM, under the optimal conditions, with a 1 nM detection limit. Precisions was of 4.5 and 2.3% for five replicate detections at 21 and 60 nM IXC, respectively. Applicability of the sensor for IXC quantification in environmental and biological samples was verified with recoveries in the range 95-106% with a relative standard deviation of <6.0%.

Novel synthesis of a dual fluorimetric sensor for the simultaneous analysis of levodopa and pyridoxine.

Herein, a fluorimetric sensor was fabricated based on molecularly imprinted polymers (MIPs) with two types of carbon dots as fluorophores. The MIPs produced had similar excitation wavelengths (400 nm) and different emission wavelengths (445 and 545 nm). They were used for the simultaneous analysis of levodopa and pyridoxine. First, two types of carbon dots, i.e. nitrogen-doped carbon dots (NCDs) with a quantum yield of 43%, and carbon dots from o-phenylenediamine (O-CDs) with a quantum yield of 17%, were prepared using the hydrothermal method. Their surfaces were then covered with MIPs through the reverse microemulsion method. Finally, a mixture of powdered NCD@MIP and O-CD@MIP nanocomposites was used for the simultaneous fluorescence measurement of levodopa and pyridoxine. Under optimal conditions using response surface methodology and Design-Expert software, a linear dynamic range of 38 to 369 nM and 53 to 457 nM, and detection limits of 13 nM and 25 nM were obtained for levodopa and pyridoxine, respectively. The capability of the proposed fluorimetric sensor was investigated in human blood serum and urine samples. Graphical Abstract Schematic representation of nitrogen-doped carbon dots (NCDs), carbon dots from o-phenylenediamine (O-CDs), NCDs coated with imprinted polymers (NCD@MIPs), and O-CDs coated with imprinted polymers (O-CD@MIPs) in the presence and absence of levodopa and pyridoxine.

Ultra-sensitive and selective electrochemical biosensor with aptamer recognition surface based on polymer quantum dots and C60/MWCNTs- polyethylenimine nanocomposites for analysis of thrombin protein.

In this study, an ultra-sensitive and selective Thrombin biosensor with aptamer-recognition surface is introduced based on carbon nanocomposite. To prepare the this biosensor, screen-printed carbon electrodes (SPCE) were modified with a nanocomposite made from fullerene (C60), multi-walled carbon nanotubes (MWCNTs), polyethylenimine (PEI) and polymer quantum dots (PQdot). The unique characteristics of each component of the C60/MWCNTs-PEI/PQdot nanocomposite allow for synergy between nanoparticles while polymer quantum dots resulted in characteristics such as high stability, high surface to volume ratio, high electrical conductivity, high biocompatibility, and high mechanical and chemical stability. The large number of amine groups in C60/MWCNTs-PEI/PQdot nanocomposite created more sites for better covalent immobilization of amino-linked aptamer (APT) which improved the sensitivity and stability of the aptasensor. Differential Pulse Voltammetry (DPV) method with probe solution was used as the measurment method. Binding of thrombin protein to aptamers immobilized on the transducer resulted in reduced electron transfer at the electrode/electrolyte interface which reduces the peak current (IP) in DPV. The calibration curve was drawn using the changes in the peak current (ΔIP),. The proposed aptasensor has a very low detection limit of 6 fmol L-1, and a large linear range of 50 fmol L-1 to 20 nmol L-1. Furthermore, the proposed C60/MWCNTs-PEI/PQdot/APT aptasensor has good reproducibility, great selectivity, low response time and a good stability during its storage. Finally, the application of the proposed aptasensor for measuring thrombin on human blood serum samples was investigated. This aptasensor can be useful in bioengineering and biomedicine applications as well as for clinical studies.

An innovative highly sensitive electrochemical sensor based on modified electrode with carbon quantum dots and multiwall carbon nanotubes for determination of methadone hydrochloride in real samples.

In the present work, to enhance the properties of a pencil graphite electrode (PGE), highly functionalized carbon quantum dots (CQDs) were synthesized and mixed with multiwall carbon nanotubes (MWCNTs) as novel modifiers for the preparation of working electrodes. These modifiers exhibited unique characteristics owing to the fascinating and well-defined properties of the CQD-MWCNT nanocomposite, including high surface to volume ratio, high conductivity, high stability and excellent electrocatalytic activity. Consequently, a modified pencil graphite electrode based on poly (diallyldimethylammonium chloride) (PDDA)/MWCNT/CQD was used to monitor the oxidation signals of methadone hydrochloride. Notably, field emission scanning electron microscopy (FE-SEM) was used to characterize the morphology and features of the different modifiers on the electrode surface. The proposed sensor was characterized via electrochemical studies including differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Under the optimum experimental conditions, the current response and concentration of methadone exhibited a linear relationship in the range of 0.1-225 µM with a detection limit of 0.03 µM. Furthermore, this sensor was successfully applied to determine methadone in human urine and plasma samples.

Ultrasensitive voltammetric and impedimetric aptasensor for diazinon pesticide detection by VS2 quantum dots-graphene nanoplatelets/carboxylated multiwalled carbon nanotubes as a new group nanocomposite for signal enrichment.

Polluted water and groundwater resources contaminated by pesticides are among the most important environmental distresses. Therefore, a simple, ultrasensitive, and selective electrochemical aptasensor is proposed for diazinon (DZN) determination as an organophosphorus compound. The vanadium disulfide quantum dots (VS2QDs) were synthesized by a facile hydrothermal method and doped on the graphene nanoplatelets/carboxylated multiwalled carbon nanotubes (GNP/CMWCNTs) as a new group of nanocomposite. The prepared nanocomposite (VS2QDs-GNP/CMWCNTs) on a glassy carbon electrode (GCE) was incubated with the DZN binding aptamer (DZBA) through electrostatic interaction (GCE/VS2QDs-GNP/CMWCNTs/DZBA). The modified electrode was used for the low detection of DZN by monitoring the oxidation of [Fe(CN)6]3-/4- as the redox probe. The characterizations of the modified electrode were performed by several electrochemical methods include: cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Also, the prepared nanocomposite was characterized with field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV-Vis absorption spectroscopy, fourier transform infrared (FT-IR), fluorescence emission spectroscopy, dynamic light scattering (DLS), elemental mapping, and energy dispersive spectroscopy (EDS). The DZBA selectively adsorbs DZN on the modified electrode, leading to a decrease and increase in the current of DPV and charge transfer resistance (RCT) of EIS, respectively, as analytical signals. The developed electrochemical aptasensor at the optimal conditions have low limits of detection (LOD) equal to 1.1 × 10-14 and 2.0 × 10-15 mol L-1 with wide dynamic ranges of 5.0 × 10-14-1.0 × 10-8 mol L-1 and 1.0 × 10-14-1.0 × 10-8 mol L-1 for DPV and EIS calibration curves, respectively. Finally, this aptasensor had good selectivity, stability, reproducibility, and feasibility for the DZN detection in various real samples.

Preparation and comparison of molecularly imprinted polymer fluorimetric nanoprobe based on polymer dots and carbon quantum dots for determination of acetamiprid using response surface method.

In this study molecularly imprinted polymers (MIP) based on carbon quantum dots (CQDs) and polymer dots (PDs) are developed for selective determination of acetamiprid using fluorometry. The measurement is based on the fluorescence quenching of CQDs and PDs in the presence of acetamiprid. PDs were prepared using a one-step aqueous synthesis method from ascorbic acid and diethylenetriamine at room temperature. CQDs were prepared from the same materials using the hydrothermal method at 180 °C. These particles were characterized using field emission scanning electron microscopy (FE-SEM), FTIR, dynamic light scattering (DLS), X-ray diffraction (XRD), UV-Vis, and fluorescence. The quantum yield was 47% for PDs and 8% for CQDs. Then, molecularly imprinted polymers (MIP) were prepared based on PDs and CQDs using reverse microemulsion method. The fluorescence quenching of CQD@MIPs and PD@MIPs was investigated at an excitation wavelength of 350 nm and emission wavelength of 440 nm in the presence of a template. Other variables affecting the fluorescence peaking were optimized using design expert software. The results illustrate that the use of PD@MIPs had a wide dynamic range 0.08-109 nmol L-1, good accuracy and detection limit of 0.02 nmol L-1, while using CQD@MIPs led to a lower dynamic range 0.36-64 nmol L-1, and detection limit of only 0.11 nmol L-1. The responses of the optical nanoprobe for acetamiprid in water (recovery 92-102%) and apple (recovery 92-103%) were also investigated. Graphical abstract Schematic representation of preparation polymer dots (PDs), carbon quantum dots (CQDs), PDs coated with imprinted polymers (PD@MIPs), and CQDs coated with imprinted polymers (CQD@MIPs) in the presence and absence of acetamiprid.

Design a fluorometric aptasensor based on CoOOH nanosheets and carbon dots for simultaneous detection of lysozyme and adenosine triphosphate.

Simultaneous detection of biomarkers and biomolecules with great analytical performance still is challenging. A simple fluorometric dual-functional aptasensor was designed to detect Lysozyme (LYS) and adenosine triphosphate (ATP) as models of a protein and a small molecule simultaneously. The sensing principle of the aptasensor is based on the interactions between cobalt oxyhydroxide CoOOH nanosheets as fluorescence quencher and carbon dots (CDs) as fluorophores. The aptamer labeled with CDs was able to assemble on CoOOH nanosheets and consequently, the fluorescence signal was quenched. With addition target analytes to the system, the aptamers folded around of targets with a strong and specific affinity. Therefore, the labeled aptamer with CDs was detached from CoOOH nanosheets and the fluorescence signal was restored. The fluorescence spectral overlap of these two CDs is the main limitation for the simultaneous analysis. The least squared support vector machine (LS-SVM) was applied to resolve this problem. Under optimal conditions, when LS-SVR was used, detection limits were found 4.0 and 1.8 nmol L-1 for ATP and LYS. The parallel biosensor is capable of monitoring ATP and LYS levels in the biological samples with satisfactory results.