As in many other methods that have integrated nanoparticles (NPs), the chemical nose/tongue strategy has also progressed greatly since the entrance of NPs into this field. The fascinating tunable ...physicochemical properties of NPs have made them powerful candidates for array-based sensing platforms and have enabled the development of real-time, sensitive and portable systems that are able to target complex mixtures of analytes. In particular, the unique optical properties of NPs have a key role in providing promising array-based sensing approaches. This review will describe the main aspects and processes of most common NP-based optical sensor arrays. The fundamental steps in the design of a sensor array together with details of each step would be provided. The review begins with the principles of optical sensor arrays and presents the concept of cross-reactivity as the main criterion in the selection of sensing elements. Changes in the absorption and emission properties of the assembled sensing elements are categorized into two main classes of optical signals (colorimetric and fluorometric). Popular chemometric methods used for analyzing the data acquired by a sensor array have also been briefly introduced. On the basis of the objective and the desired application, different types of plasmonic and fluorescent NP that possess unique opto-physical properties have been presented as available choices in the design of sensing elements. The vast number of applications of NP-based optical sensor arrays published throughout the literature have then been reviewed according to their mechanism of interaction and the type of optical signal. Finally, the remaining challenges and future directions in this topic have been highlighted.
Recent progress in nanoparticle-based optical sensor arrays toward the detection and discrimination of a wide range of analytes.
Catecholamine neurotransmitters, generally including dopamine (DA), epinephrine (EP) and norepinephrine (NE) are known as substantial indicators of various neurological diseases. Simultaneous ...detection of these compounds and their metabolites is highly recommended in early clinical diagnosis. To this aim, in the present contribution, a high performance colorimetric sensor array has been proposed for the detection and discrimination of catecholamines based on their reducing ability to deposit silver on the surface of gold nanorods (AuNRs). The amassed silver nanoshell led to a blue shift in the longitudinal localized surface plasmon resonance (LSPR) peak of AuNRs, creating a unique pattern for each of the neurotransmitters. Hierarchical cluster analysis (HCA) and linear discriminate analysis (LDA) pattern recognition techniques were employed to identify DA, EP and NE. The proposed colorimetric array is able to differentiate among individual neurotransmitters as well as their mixtures, successfully. Finally, it was shown that the sensor array can identify these neurotransmitters in human urine samples.
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Malathion is an organophosphorus insecticide widely used in agriculture, residential area, and public health programs with a known mechanism of toxicity of inhibition of acetylcholinesterase and ...induction of oxidative stress. Gold nanoparticles (AuNPs) represent stable and easily synthesized nanoparticles with extensive use in consumer products and medicine. Due to the antioxidant property of AuNPs, it is possible that AuNPs may prevent malathion-induced oxidative damage. In this study, the cytotoxicity of malathion and AuNPs (10 and 20 nm) were measured separately in Caco-2 cells. Then the protective effects of AuNPs were evaluated by measuring the oxidative stress (lipid peroxidation level and glutathione content) and acetylcholinesterase activity. The calculated IC50s values at 48 hr were 326.8±0.32, 43.09±0.65, and 41.46±0.24 µg/ml for malathion, AuNPs 10 and 20 nm, respectively. Then, the lowest concentration of AuNPs (1 µg/ml) and IC50 concentration of malathion (326.8 µg/ml) were selected to evaluate the effects of pretreatment of Caco-2 cells with AuNPs before exposure to malathion were evaluated. Interestingly, the results showed remarkably significant protective effects of AuNPs by attenuation the different parameters of oxidative stress and cytotoxicity induced by malathion in cells (P<0.001). It is the first report showing the protective effects of AuNPs against malathion-induced cytotoxicity in the Caco-2 cell line.
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Signal generation techniques for visual detection of analytes have received a great deal of attention in various sensing fields. These approaches are considered to be advantageous when ...instrumentation cannot be employed, such as for on-site assays, point-of-care tests, and he althcare diagnostics in resource-constrained areas. Amongst various visual detection approaches explored for non-invasive quantitative measurements, ratiometric fluorescence sensing has received particular attention as a potential method to overcome the limitations of intensity-based probes. This technique relies on changes in the intensity of two or more emission bands (induced by an analyte), resulting in an effective internal referencing which improves the sensitivity of the detection. The self-calibration, together with the unique optophysical properties of nanoparticles (NPs) have made the ratiometric fluorescent nanoprobes more sensitive and reliable, which in turn, can result in more precise visual detection of the analytes. Over the past few years, a vast number of ratiometric sensing probes using nanostructured fluorophores have been designed and reported for a wide variety of sensing, imaging, and biomedical applications. In this work, a review on the NP-based ratiometric fluorescent sensors has been presented to meticulously elucidate their development, advances and challenges. With a special emphasis on visual detection, the most important steps in the design of fluorescent ratiometric nanoprobes have been given and based on different classes of analytes, recent applications of fluorescent ratiometric nanoprobes have been summarized. The challenges for the future use of the technique investigated in this review have been also discussed.
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•Ratiometric fluorescent nanoprobes are known as promising sensing tools.•Ratiometric probes provide distinguishable color changes for visual detection.•The internal referencing in ratiometric probes greatly enhances their sensitivity.•Visual detection is helpful for onsite monitoring in resource-constrained areas.•Ratiometric design requires rational manipulation of nanostructured fluorophores.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Pattern-based sensing with multi-component sensor arrays, despite its merits, may be laborious and time-consuming. As an alternative approach, herein, a condition-based single component sensor array ...has been provided which represents an elegantly simple, low cost and minimally instrumented format for the quantification and classification of antidepressants (ADs). Tuning the pH and ionic strength enabled the single component probe to interact with the target analytes through different binding modes, providing the required cross-reactivity for multiplex detection. The analytical figures of merit verified that the condition-based sensor array is precise and accurate in both the discrimination and quantification of the ADs. Excellent sensitivity and selectivity were achieved in the discrimination of the ADs. Moreover, low limit of detections (as low as 0.009 μg.mL−1) and wide linear ranges (up to four orders of magnitude) were attained in the multivariate calibration of each AD. The results of multivariate calibration (R2cal>0.99 and R2cv>0.99) and classification (sensitivity 100% and specificity 100%) of ADs in human urine ensured the practicability of the array in complex biological fluids. Furthermore, the wide-ranging colorimetric responses that appeared due to the different environment sensitive aggregation patterns allowed visual detection.
•Providing distinct colorimetric patterns via fine control of pH and ionic strength.•Visual discrimination of antidepressants with wide-ranging colorimetric responses.•Triggering cross-reactivity by tuning buffer characteristics.•Differential aggregation patterns delivered by a condition-based sensor array.•Quantification and classification of antidepressant drugs in human urine.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Today, RNA aptamers are being considered promising theranostic tools against a wide variety of disorders. RNA aptamers can fold into complex shapes and bind to diverse nanostructures, macromolecules, ...cells, and viruses. It is possible to isolate RNA aptamers from a vast pool of nucleic acids via the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method. As therapeutics, aptamers have great potential because of their ability to bind to proteins and selectively limit their activities with negligible side effects. Several RNA aptamers with potential implications in cancer diagnosis are known to confer a great affinity for single-stranded DNA molecules, long non-coding RNAs, circulating tumor cells, vascular endothelial growth factors, and tissue and sera-derived exosomes in patients with different malignancies. Furthermore, clinical investigations have revealed the efficacy of RNA aptamer-based agents in imaging modalities. This review seeks to deliver new insights into the development, classification, nanomerization, and modification of RNA aptamers, as well as their applications in cancer theranostics. The aptamers’ mechanism of action and their interest to clinical trials as theranostic agents are also discussed.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A low cost colorimetric microfluidic paper-based analytical device (µPAD) for the determination of nitrite in real samples with improved precision has been fabricated and its performance has been ...evaluated. The µPAD was fabricated by laser cutting and patterning on the paper and the nitrite concentration measurement is based on the modified Griess assay. In this assay, tartaric acid was used as an antioxidant reagent to increase Griess reagent stability. A novel geometrical design was used to achieve better color gradient over µPAD detection zone for improving the precision of the measurements. The results of measurement indicate that the fabricated device could successfully detect and quantify the nitrite concentration in real samples with the limit of detection of 15 μM. The results are in good accordance with the results of spectrophotometry. The fabricated sensor has the potential to be applied for monitoring of the trace level of nitrite in drinking water and environmental applications.
The aim of current study was to illustrate a strategy to encapsulate itraconazole into chitosan-based nanoparticles using a modified ionic gelation method and to fabricate them as inhalable ...microparticles using spray drying technique. Different ratios of chitosan:tripolyphosphate (TPP) were prepared at pH 1.2, using higher ratios of TPP with respect to chitosan. The highest encapsulation efficiency of itraconazole into chitosan nanoparticles was found to be about 55% at 1:3 ratio of chitosan:TPP. Increasing the amount of TPP 4 times higher than chitosan resulted in the production of large particles in micron scale. Below the ratio of 1:3, the particle sizes ranged from 190 to 240nm. Nanoparticles were characterized for morphology by TEM images. Microparticles were prepared by co-spray drying of nanoparticles with 2.5, 10 and 20% of lactose and mannitol with or without 10% of leucine, with respect to nanoparticle weights. In vitro inhalation parameters including fine particle fraction (FPF) and emitted dose percentage (ED%) were measured by a twin stage impinger (TSI). The in vitro deposition data indicated that processing of nanoparticles with mannitol and leucine could improve the aerosolization properties of the drug significantly.
Itraconazole was encapsulated into the chitosan:tripolyphosphate nanoparticles at pH 1.2, using higher ratios of tripolyphosphate with respect to chitosan. The nanoparticles were spray dried in the presence of lactose, mannitol and/or leucine. In vitro deposition tests were performed using a twin stage impinger. Processing of nanoparticles with mannitol and leucine improved the aerosolization properties of the drug significantly. Display omitted
► ITRA at pH 1.2 was used to make more stable and efficient complexation with HPβCD. ► Chitosan:TPP nanoparticles entrapped ITRA-HPßCD by ionic gelation method at low pH. ► Spray dried powders containing mannitol exhibited higher aerosolization behavior. ► The presence of leucine increased significantly the pulmonary deposition parameters.
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•Prenatal exposure to AgNPs can penetrate into the fetal brain.•AgNPs is able to induce cognitive and behavioral abnormality in adult offspring.•AgNPs at low concentrations can damage ...the brain function.•Mitochondria and innate immune system are involved in brain damage.•The brain toxicity of AgNPs depends on the size of nanoparticle.
Silver nanoparticles (Ag-NPs) are currently used in a wide range of consumer products. Considering the small size of Ag-NPs, they are able to pass through variety of biological barriers and exert their effects. In this regard, the unique physicochemical properties of Ag-NPs along with its high application in the industry have raised concerns about their negative effects on human health. Therefore, it investigated whether prenatal exposure to low doses of Ag-NPs is able to induce any abnormality in the cognitive and behavioral performance of adult offspring. We gavaged pregnant NMRI mice with, 1) Deionized water as vehicle, 2) Ag-NPs 10 nm (0.26 mg/kg/day), 3) Ag-NPs 30 nm (0.26 mg/kg/day), and 4) AgNO3 (0.26 mg/kg/day) from gestational day (GD) 0 until delivery day. At the postnatal day (PD) 1, our results showed that high concentration of silver is present in the brain of pups. Further, we observed mitochondrial dysfunction and upregulation of the genes relevant to innate immune system in the brain. At PD 60, results revealed that prenatal exposure to Ag-NPs provoked severe cognitive and behavioral abnormalities in male offspring. In addition, we found that prenatal exposure to Ag-NPs was associated with abnormal mitochondrial function and significant up-regulation of the genes relevant to innate immunity in the brain. Although the Ag-NPs have been considered as safe compounds at low doses, our results indicate that prenatal exposure to low doses of Ag-NPs is able to induce behavioral and cognitive abnormalities in adulthood. Also, we found that these effects are at least partly associated with hippocampal mitochondrial dysfunction and the activation of sterile inflammation during early stages of life.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Catecholamine neurotransmitters, specifically, dopamine (DA), epinephrine (EP), and norepinephrine (NE), are known as substantial indicators of various neurological diseases. Developing rapid ...detection methods capable of simultaneously screening their concentrations is highly desired for early clinical diagnosis of such diseases. To this aim, we have designed an optical sensor array using three fluorescent dyes with distinct emission bands and have monitored variations in their emission profiles upon the addition of DA, EP, and NE in the presence of gold ions. Because of the different reducing power of catecholamines, differently sized gold nanoparticles (GNPs) with different levels of aggregation were generated, resulting in different amounts of spectral overlap between the absorption band of the in situ generated plasmonic GNPs and the emission bands of the fluorescent dyes. These energy-transfer-based fingerprint profiles were used to discriminate the neurotransmitters by applying pattern recognition methods including linear discriminant analysis (LDA) and artificial neural networks (ANN) and to determine their concentration using multiple linear regression (MLR). Our proposed array also showed a good performance in the discrimination of DA, EP, and NE in complex biological media such as human urine.
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