Lower Limit Research Articles

Highly sensitive volatile organic compounds monitoring enabling by silver-nanowire@metal–organic frameworks core-shell heterostructure

Metal–organic frameworks (MOFs) hold great promise as advanced chemical sensing materials due to their high surface area and tunable surface chemistry. However, due to the inherent conductivity, building a highly sensitive MOFs-based gas sensor for real-time monitoring hazardous gas operated at room temperature (RT) is still a huge challenge. Herein, an in-situ anchoring strategy is proposed to construct a 1D-0D core-shell heterostructure by integrating silver nanowires (AgNWs) with highly conductivity and Zn-MOF with high specific surface area. The incorporation of AgNWs establishes a highly conductive network architecture to facilitate rapid charge transport while preventing the Zn-MOF nanoparticles from agglomeration, ensuring an effective transmission highway for target gas molecules. Meanwhile, the Zn-MOF nanoparticles induce remarkable absorption capacity and contribute high gas response. By strategically amalgamating the inherent distinctive virtues of the individual components and capitalizing on the synergistic benefits arising from the composite, the sensors hinged upon the refined AgNWs@Zn-MOF (A@Z) heterostructure unveiled remarkable response value of 27 to 20 ppm ethanol at RT, accompanied by a low detection limit of 1 ppm. Moreover, the A@Z sensor further showcases superior selectivity and repeatability. This work offers a fresh standpoint for the fabrication of MOF-based heterostructures, fostering advancements in diverse applications.

A long-wavelength fluorescent probe based on carbazole with AIE characteristics for the detection of ONOO− and its application

Peroxynitrite (ONOO−) is an important reactive oxygen species, and excess ONOO− in the body can lead to a range of diseases. Addressing the need for sensitive detection ONOO−, in this work, a highly sensitivity and selectivity long-wavelength fluorescent probe (named CIS) was designed for tracking ONOO− in biological cells. Probe CIS featured carbazole as the fluorophore and the CC double bond with two electron withdrawing –CN groups as the recognition site. The probe CIS exhibited the typical aggregation-induced emission (AIE) and intramolecular charge transfer (ICT) characteristics with the bright red fluorescent emission in high water fraction (fw ≥ 50 %) and negligible emission in low water fraction. The fluorescence emission wavelength of probe CIS is 631 nm, with a large Stokes shift (151 nm), which can sensitively detect ONOO− in DMSO: H2O (7:3, v/v) environment. Notably, the probe CIS exhibited a wide pH detection range (pH = 3–10), a low detection limit of 36.66 nM, high selectivity and minimal interference. Furthermore, probe CIS demonstrated excellent biocompatibility and low cytotoxicity, and can be used for the detection of exogenous ONOO− in 4T1 cells (Mouse breast cancer cells). These research results indicate that probe CIS has potential application prospects in the biological aspects.

SERS aptasensor for simultaneous detection of ochratoxin A and zearalenone utilizing a rigid enhanced substrate (ITO/AuNPs/GO) combined with Au@AgNPs

The contamination of mycotoxins poses a serious threat to global food security, hence the urgent need for simultaneous detection of multiple mycotoxins. Herein, two SERS nanoprobes were synthesized by embedded SERS tags (4-mercaptopyridine, 4MPy; 4-mercaptobenzonitrile, TBN) into the Au and Ag core–shell structure, and each was coupled with the aptamers specific to ochratoxin A (OTA) and zearalenone (ZEN). Meanwhile, a rigid enhanced substrate Indium tin oxide glass/AuNPs/Graphene oxide (ITO/AuNPs/GO) was combined with aptamer functionalized Au@AgNPs via π-π stacking interactions between the aptamer and GO to construct a surface-enhanced Raman spectroscopy (SERS) aptasensor, thereby inducing a SERS enhancement effect for the effective and swift simultaneous detection of both OTA and ZEN. The presence of OTA and ZEN caused signal probes dissociation, resulting in an inverse correlation between Raman signal intensity (1005 cm−1 and 2227 cm−1) and the concentrations of OTA and ZEN, respectively. The SERS aptasensor exhibited wide linear detection ranges of 0.001–20 ng/mL for OTA and 0.1–100 ng/mL for ZEN, with low detection limits (LOD) of 0.94 pg/mL for OTA and 59 pg/mL for ZEN. Furthermore, the developed SERS aptasensor demonstrated feasible applicability in the detection of OTA and ZEN in maize, showcasing its substantial potential for practical implementation.

Cubic structured zinc ferrite methodically incorporated into porous graphene sheets as a selective Electrocatalyst for electrochemical detection of Carbendazim

Carbendazim (CBZ) insecticides have been widely employed, raising serious concerns about their impacts on human health and the environment. A facile hydrothermal technique was used to prepare a zinc ferrite (ZnFe₂O₄) combined with porous graphene oxide (PGO) as a nanocomposite for selective CBZ detection. The ZnFe₂O₄/PGO nanocomposite was then used to modify a glassy carbon electrode (GCE), an affordable platform for CBZ detection. Various spectroscopic techniques were employed to confirm the nanomaterial. The electrochemical properties were further investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The ZnFe₂O₄/PGO nanocomposite modified the glassy carbon electrode surface for CBZ detection. A broad linear response range of 0.0039 to 200 μM, high sensitivity (2.184 μAμM−1 cm−2), a low detection limit of 0.0013 μM, outstanding stability, repeatability, and practical applicability are the intriguing qualities of the ZnFe₂O₄/PGO-modified electrode for CBZ detection.

Construction and application of bifunctional AIE fluorescent probe for the detection of Cys and viscosity

A bifunctional fluorescent probe, A-1, was designed and synthesized for the recognition of Cys and viscosity. In the high-viscosity system, the intramolecular rotation of A-1 is restricted, which activates its near-infrared fluorescence. Simultaneously, the probe specifically detects Cys using acrylate as the recognition site. It possesses advantages such as high sensitivity, low detection limit, large Stokes shift (140 nm), high selectivity, and anti-interference properties. In addition, the probe A-1 can target mitochondria before recognition, and aggregate in lipid droplets after reacting with Cys. Based on the above excellent properties, it has been used to monitor changes in Cys and viscosity levels in living cells. And for the first time, it has revealed fluctuations in Cys and viscosity levels in the apoptosis model induced by Cisplatin. This provides a powerful tool for an in-depth study of related disease mechanisms.

Preparation of a multiple interacting magnetic fluid for rapid and sensitive simultaneous extraction of β-nicotinamide mononucleotide metabolites in biological samples

Backgroundβ-nicotinamide mononucleotide stands out as an essential breakthrough in “anti-aging” and consistently leads the list of top-selling nutritional supplements in terms of quantity. As the metabolites of β-nicotinamide mononucleotide, the detection of nicotinamide and N1-methylnicotinamide is of great significance for evaluating the nutritional effect of dietary supplements of β-nicotinamide mononucleotide. However, due to the extremely low concentration of nicotinamide and N1-methylnicotinamide in vivo and the serious matrix interference in biological samples, there is an increasing demand for materials and methods of pre-treatment. ResultsIn this study, Fe3O4@hydroxypropyl methyl cellulose@dodecylbenzenesulfonic acid magnetic fluid was synthesized for the first time, and it was used as pretreatment material to detect nicotinamide and N1- methylnicotinamide in urine samples by high performance liquid chromatography. Compared with other adsorption materials, Fe3O4@hydroxypropyl methyl cellulose@dodecylbenzenesulfonic acid nanoparticles are a kind of uniform magnetic fluid. Furthermore, they have more types and quantities of interaction sites (electrostatic interactions, hydrophobic interactions, hydrogen bonding interactions, and π-π interactions), so they own greater adsorption capacity. When the pH of the solution is 4, they can be adsorbed quickly within 10 s. The method successfully detected trace nicotinamide and N1-methylnicotinamide in urine samples in the linear range of 0.1–80 μg mL−1, the low detection limits were 0.30 ng mL−1 and 1.5 ng mL−1 respectively, and the quantification limits were 1.0 ng mL−1 and 5.0 ng mL−1, respectively. At the same time, the standard urine samples of nicotinamide and N1-methylnicotinamide showed satisfactory recovery rate 94.50–109.1 %. The results indicated that the established method can accurately and quantitatively determine trace nicotinamide and N1-methylnicotinamide in urine samples. SignificanceConsequently, low concentration of β-nicotinamide mononucleotide metabolites can be detected simultaneously, and the interference can be eliminated during the detection process, which provides an efficient and convenient pretreatment method and a rapid and sensitive detection method for the analysis of β-nicotinamide mononucleotide metabolites. What's more, it has a wide application prospect in the analysis of other similar metabolites in biological samples.

Development of a novel isophorone-derived near-infrared fluorescent probe for specific and visual detection of Pb2+: Theoretical, practical and bioimaging investigations

The development of specific and visually detectable fluorophores for the accurate and rapid Pb2+ recognization is crucial. In this study, we introduced a novel isophorone-derived fluorescent probe, (E)-2-(3-(3-formyl-4-hydroxystyryl)-5,5-dimethylcyclohex-2-en-1-ylidene)malononitrile (YSQ), rationally designed for prompt and high-quality Pb2+ detection. YSQ demonstrated noticeable red emitting fluorescence enhancement upon Pb2+ interactions (upon binding, τavg 16.7 ns, Φ 12 %) with visible color changes discernible to the naked eye in MeOH/H2O (v/v 9/1, pH 7.4, 0.2 mM). The probe YSQ achieved a quite low detection limit (LOD) of 18 nM and a high association constant of 2.93 × 105 M−1 towards Pb2+ using fluorescence titration. We proposed a binding mechanism of YSQ with Pb2+ ions, supported by the density functional theory (DFT/TD-DFT), 1H NMR titration experiments, IR and HRMS analysis. In addition, a simple and affordable smartphone-supported specific Pb2+ detection technique was developed with visible color changes. Furthermore, this NIR emissive properties of YSQ offered broad potential applications in actual water sample and solid analysis, bio-imaging and test strips.

A dual-potential electrochemiluminescence sensor for glutamate pyruvate transaminase detection based on AgNPs/N, S-GQDs modified paper-based electrode

The liver, one of the most vital organs in the human body, relies on glutamate pyruvate transaminase (GPT) as a sensitive indicator of hepatocellular injury, making it a cornerstone parameter in liver function assessment. This study employed a paper-based electrode modified with AgNPs/N, S-GQDs synthesized via pyrolysis to construct an AgNPs/N, S-GQDs paper-based electrode reaction system for detecting GPT activity across two potential ranges. This approach involved utilizing electrochemiluminescence (ECL) detection to indirectly measure GPT levels by detecting the NADH generated through GPT transamination, as well as investigating the relationship between GPT activity and the ECL intensity of the reaction system directly. Experimental results demonstrated a robust linear correlation between GPT activity and the ECL intensity of the reaction system within the ranges of 1U/L to 1000U/L and 5U/L to 200U/L, with detection limits of 0.24U/L and 3.73U/L, respectively. By establishing methods for indirect and direct GPT detection within the same reaction system across different scan ranges, this study enhances detection accuracy. The proposed method not only offers a wide linear range and low detection limits for GPT detection but also exhibits notable advantages in terms of detection efficiency compared to other methods, showcasing promising applications in the diagnosis and evaluation of liver function-related diseases.

Synthesis of porous SnO2@Fe2O3 core-shell triple-shelled boxes with selective and rapid response towards HCHO

Heterogenous SnO2@Fe2O3 core-shell triple-layer boxes (TBs) are successfully prepared through using a combination of room-temperature hydrolyzation and annealing treatment on SnO2 double-layer boxes (DBs). The crystallinity, morphology, and microstructure of as-prepared SnO2@Fe2O3 TBs are detailedly characterized. Compared with those of referenced pristine SnO2 or Fe2O3 nanostructures, the overall cubic configuration of heterogeneous SnO2@Fe2O3 with hollow interiors retains largely unaltered. Meanwhile, sensor based on SnO2@Fe2O3 samples synthesized with Fe2O3/SnO2 mole ratio of 1 exhibit superior response, excellent selectivity, shortened response-recovery time, and good long-time stability for formaldehyde (HCHO). It has the highest response (11.72) with the response/recovery time of 4 s/19 s to 50 ppm HCHO, respectively, and a low detection limit (1.07 to 200 ppb) for targeted HCHO under the optimal operating temperature (220 °C). The high absorption ability based on unique structural merits of hierarchically SnO2/Fe2O3 subunit-assembled porous multilayers and synergistic effect of SnO2/Fe2O3 heterojunction may contribute to their excellent HCHO sensing performance.

Layer-by-layer fabrication of covalent organic frameworks on stainless steel needles as solid-phase microextraction probe coupled with electrospray ionization mass spectrometry for enrichment and determination of tyrosine kinase inhibitors in biosamples

Sunitinib, N-desmethyl imatinib, dasatinib, imatinib, and bosutinib are tyrosine kinase inhibitors (TKIs) that are commonly employed in the treatment of a multitude of cancers. However, the inappropriate concentrations of TKIs can result in ineffective treatment or the emergence of multiple adverse effects. Consequently, the development of a rapid and sensitive analytical method for TKIs is of paramount importance for the safe administration of drugs. In this work, solid-phase microextraction (SPME) probe combined with an electrospray ionization mass spectrometry (ESI-MS) coupling platform was constructed for rapid and sensitive determination of TKIs. The covalent organic frameworks (COFs) coated SPME probe was made of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and 2,5-dibutoxyterephthalaldehyde (DBTA) by in-situ layer-by-layer chemical bonding synthesis strategy. The TAPT-DBTA-SPME probe exhibited several advantageous properties which rendered it suitable for the enrichment of TKIs. Under the optimal conditions, the developed analytical method demonstrated a broad linear range (0.05–500.00 µg/L), a low limit of detection (0.02 µg/L) and a high enrichment factor (51–203) for TKIs. The developed analytical method was successfully applied to a pharmacokinetic study of TKIs in mouse plasma and tissue matrix, demonstrating that the proposed analytical method has promise for clinical applications and metabolic monitoring.

An effective procedure used metal–organic framework for determination of cadmium ions in real tap water and human blood plasma samples

A newly developed 2H5MA-MOF sensor by covalently linking NH2-MIL-53(Al) with 2′-Hydroxy-5′-methylacetophenon, designed for highly sensitive and selective detection of Cd2+ ions using fluorometric methods. Detailed structural and morphological analyses confirmed the sensor’s unique properties. It demonstrated an impressive linear detection range from 0 to 2 ppm, with an exceptionally low detection limit of 5.77 × 10−2 ppm and a quantification limit of 1.75 × 10−1 ppm, indicating its high sensitivity (R2 = 0.9996). The sensor also responded quickly, detecting Cd2+ within just 30 s at pH 4. We successfully tested it on real samples of tap water and human blood plasma, achieving recovery rates between 96 % and 104 %. The accuracy of these findings was further validated by comparison with ICP-OES. Overall, the 2H5MA-MOF sensor shows great potential for fast, ultra-sensitive, and reliable detection of Cd2+ ions, making it a promising tool for environmental and biomedical applications.

Centrifugated lateral flow assay strips based on dual-emission carbon dots modified with europium ions for ratiometric determination and on-site discrimination of tetracyclines in environment

Due to the serious detrimental impact on human health, antibiotic pollution particularly tetracyclines residues has become a serious problem. Herein, a multiple response fluorescent probe consisted of dual-emission carbon dots and Eu3+ (D-CDs@Eu3+) is designed for the determination and discrimination of tetracyclines (TCs). Specifically, the carboxyl and amidogen group of dual-emission carbon dots (D-CDs) can coordinate with Eu3+ to form the D-CDs@Eu3+. Upon adding TCs, the fluorescence intensities of D-CDs at 405 nm and 495 nm are quenched due to inner filter effect (IFE) and the localization of fluorescence resonance energy transfer (L-FRET) between the D-CDs@Eu3+ and TC. Simultaneously, the D-CDs@Eu3+ may chelate with TCs to enhance the occurrence of antenna effect, while the characteristic peaks of Eu3+ at 590 nm and 615 nm are enhanced. On these bases, the TCs detection is achieved with low detection limits from 46.7 to 72.0 nM. Additionally, through the distinct efficiencies of L-FRET, the discrimination of TCs is achieved. Moreover, a novel centrifugated lateral flow assay strips (CLFASs) device is developed by integrating the D-CDs@Eu3+, lateral flow assay strips and smartphone using RGB variations for TCs detection, achieving remarkable recoveries (98.6–103.7 %) in real samples. Therefore, this CLFASs device provides a reliable approach for the TCs detection, demonstrating potential applications.

Heterostructures constructed by NiMoO4 functionalized 2D MoO3 nanosheets for ultrasensitive trimethylamine detection with ppb level detection

Trimethylamine (TMA) serves as an indicator for assessing seafood spoilage and a biomarker for kidney disease. Achieving this dual functionality necessitates the detection of TMA with a low detection limit and exceptional selectivity. Here, NiMoO4 functionalized MoO3 heterostructures were constructed and subjected to a systematic investigation of their sensing properties towards TMA. The 7 %-NiMoO4/MoO3 sensor could detect trace TMA at 200°C with a response value of 3.93 (0.1 ppm) and achieve detecting thresholds as low as 2.48 ppb (theoretical limit). Additionally, the sensor exhibits remarkable selectivity to TMA, an expansive adjustable concentration on detection range, and excellent long-term stability. The enhanced sensing properties may be ascribed to the forming p-n heterojunctions at the NiMoO4/MoO3 interface, effectively modulating the interfacial potential. Moreover, the NiMoO4/MoO3 heterostructures demonstrate excellent charge-transfer capability, high charge carrier density, and a substantial active surface area in electrochemical measurements, thereby enhancing the sensing ability of TMA. Additionally, the thin nanosheet structure facilitates efficient charge transportation along the length of the nanosheets, further enhancing the sensing response. These results indicate the potential of NiMoO4/MoO3 as a promising sensing material for TMA gas sensors.

In2O3 electrochemical transistors based on PtAu4/RGO nanocomposites functionalized gate for highly sensitive nitrite detection

Nitrite is commonly found in the environment, but its overuse and potential toxicity pose serious health risks. There is a strong need to develop robust and reliable methods for detecting nitrite. Herein, a novel In2O3 solution-gated electrochemical transistor (SGET) nitrite sensor was designed and fabricated for highly sensitive detection of nitrite. Different thicknesses of In2O3 thin films were prepared by sol–gel method, which were used as the channel of transistors and optimized through evaluating the electronic and electrochemical properties. To improve the catalytic oxidation of nitrite, PtAu4 nanoparticles modified reduced graphene oxide nanocomposites (PtAu4/RGO) were fabricated on the gate of transistors through electrodeposition approach. The developed sensor exhibited exceptional sensing performance in nitrite detection, which featured with low detection limit (0.1 nM nitrite) and ultra-wide linear range from 0.1 nM to 1 mM. The developed In2O3 SGET sensor displayed excellent stability and high resistance to common interfering ions, thereby demonstrating superior anti-interference performance. Nitrite in real samples of natural lake water has been accurately measured, suggesting that the designed sensor could act as an ideal transducer platform for highly sensitive and selective nitrite detection in food and environmental fields.

Superassembled Mesoporous Carbon-Fe2O3 Heterochannels for Photothermal-Enhanced Hyaluronidase Sensing

Superassembled Mesoporous Carbon-Fe₂O₃ Heterochannels for Photothermal-Enhanced Hyaluronidase Sensing

Cu,Ce-containing phosphotungstates as laccase-like nanozyme for colorimetric detection of Cr(VI) and Fe(Ⅲ)

Herein, a nanocomposite of Cu,Ce-containing phosphotungstates (Cu,Ce-PTs) with outstanding laccase-like activity was fabricated via a one-pot microwave-assisted hydrothermal method. Notably, it was discovered that both Fe3+ and Cr6+ could significantly enhance the electron transfer rates of Ce3+ and Ce4+, along with generous Cu2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe3+ and Cr6+ in a range of 0.667–333.33 μg/mL and 0.033–33.33 μg/mL with a low detection limit of 0.135 μg/mL and 0.0288 μg/mL, respectively. The proposed assay exhibits excellent reusability and selectivity and can be used in traditional Chinese medicine samples analysis.

Triiodothyronine levels in athyreotic pediatric patients during levothyroxine therapy.

Levothyroxine (LT4) monotherapy is the current recommended approach for treating pediatric patients post-total thyroidectomy (TT) based on the assumption that peripheral conversion of thyroxine (T4) to triiodothyronine (T3) normalizes thyroid hormone levels. In adults, approximately 15% of post-TT patients on LT4 monotherapy have altered T4:T3 ratios with ongoing debate in regard to the clinical impact with respect to health-related quality of life (hrQOL). The ability to normalize T3 and T4 levels on LT4 monotherapy for pediatric patients' post-TT is important but not previously described. This study reports data on T3 levels in athyreotic pediatric patients to determine if a similar cohort of patients exists on LT4 monotherapy targeting normalization of TSH (LT4 replacement) or suppression (LT4 suppression). Thyroid function tests (TFTs) were retrospectively extracted from medical charts for patients <19 years old who underwent TT for definitive treatment of Graves' disease (GD) or differentiated thyroid cancer (DTC) between 2010-2021. LT4 dosing was selected to normalize the TSH in GD patients (LT4 replacement) or suppress TSH in DTC patients (LT4 suppression). Pre- and post-surgical TSH, T3 and T4 levels were compared. Of 108 patients on LT4 replacement (n=53) or LT4 suppression (n=55) therapy, 94% (102/108) of patients demonstrated T3 levels in the normal range post-TT. However, the majority of patients on LT4 replacement (44/53; 83%) and LT4 suppression (31/55; 56%) displayed post-TT T3 levels in the lower half of the normal range despite 50% (22/44) and 48% (15/31) of these patients, respectively, having post-TT fT4 levels above the upper limit of the normal range. A significant number of pediatric patients do not achieve similar T3 and T4:T3 levels pre- and post-TT. Future multi-center, prospective studies evaluating LT4 monotherapy in comparison to combined LT4/LT3 therapy are warranted to determine the potential clinical impact of altered T3 levels in athyreotic pediatric patients.

Eu(III)-functionalized metal–organic framework as a visual ratiometric fluorescence sensor for rapid discrimination and detection of multiple tetracyclines in agricultural products

The misuse of oxytetracycline (OTC), doxycycline (DOX), tetracycline (TC), and chlortetracycline (CTC) poses a serious threat to human health and it calls for rapid and visual methods. In this study, a novel ratio fluorescent sensor was constructed by simply combining Eu(III) with IRMOF-3. Spectral characterization and DFT theoretical calculations revealed different mechanism of interactions between the MOF-based sensor and different tetracyclines in detail. PCA analysis amplified these differences, enabling the simultaneous identification and differentiation of individual, binary or ternary mixtures of multiple tetracyclines. Subsequently, a rapid fluorescence sensing method (<5 min) for detecting OTC, DOX, TC, and CTC was established with low detection limits of 70, 75, 40, and 168 nM, respectively, which are all below the maximum residue limits by the European Union and the U.S. Food and Drug Administration regulations. A portable visual test strip was also conducted based smartphone with low detection limits of 1 μM, exhibiting an obvious color spectrum transition from blue to purple and finally to pink. Furthermore, the sensor was applied successful to pig feed, milk and veterinary drugs. The results showed good agreement with HPLC-MS/MS analysis.

Nickel-doped tungsten fabricated electrode for electrochemical sensing of amoxicillin

One of the most popular antibiotics used in human medicine is amoxicillin (AML). It is frequently applied to humans and animals to avoid or treat infections caused by bacteria. However, considering its widespread application and excessive use of AML, it could harm the environment and the general world because of the hazardous potential of its pharmaceutical industry effluents. Additionally, some unpleasant compounds might be left behind due to the extensive use of these animals in food production. Hence, AML may be the root cause of several illnesses, including rashes, nausea, vomiting, and colitis linked to antibiotics, if it is present in biological fluids in sufficient quantities. Aquatic habitats where it accumulates can give rise to bacterial species that are susceptible to it. Novel electroanalytical methods with sensitive and quick examination abilities are required to identify and quantify the level of AML in drugs, biological fluids, environmental pollutants, and foods. We have developed a novel sensor that quantitatively detects AML using a modified carbon paste electrode containing nickel-doped tungsten oxide (Ni-WO3). Findings show that Ni-WO3 acts as an electrocatalyst in the oxidation of AML. AML-wide concentration showed a strong linear response from this electrocatalytic oxidation encompassing the range of 0.05 μM to 0.9 μMwith a low detection limit of 8.68 × 10−9 M. As a result, the current electrocatalytic method provides a quick, accurate, and simple method to detect AML in biological medium and pharmaceutical formulations. A sensor with excellent reproducibility, short response times, and outstanding stability has been described as the modified electrode.

Ultrasensitive electrochemical sensing for simultaneous rapid detection of zearalenone and ochratoxin A in feedstuffs and foodstuffs

Mycotoxins are causing persistent worries regarding food safety worldwide due to their ability to elicit a wide range of harmful effects in both animals and humans. Approaches that can identify a single mycotoxin are not sufficient for addressing the needs of quality control of agricultural products since they are often co-contaminated by multiple mycotoxins. This paper presents the development of an electrochemical sensor that is free of biomolecules and is capable of simultaneously detecting zearalenone (ZEN) and ochratoxin A (OTA) through the incorporation of nickel oxide (NiO) with carboxylated carbon nanotubes (MWCNT(–COOH)).This is the first time that NiO–MWCNT(–COOH) based electrochemical sensor has achieved the simultaneous potential-resolved selective detection of ZEN and OTA. Under optimized conditions, good linear responses were observed in the range of 0.01–10.24 μg mL−1 for ZEN and 0.04–10.24 μg mL−1 for OTA with low detection limit of 6 and 15 ng mL−1, respectively. The proposed electrochemical sensor demonstrated good selectivity, reusability, reproducibility, and shelf-life for the sensitive detection of both mycotoxins. Moreover, the sensor was made utilizing screen-printing technology to demonstrate its potential for commercialization and practical application. Our biomolecule-free electrochemical sensor was successful in evaluating these mycotoxins in actual samples of corn flour and wheat flour, proving its promising application in monitoring ZEN and OTA co-contamination in agricultural products.