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An ELIME assay for hepatitis A virus detection. Talanta 2021; 234:122672. [PMID: 34364473 DOI: 10.1016/j.talanta.2021.122672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/24/2021] [Accepted: 06/26/2021] [Indexed: 10/20/2022]
Abstract
An Enzyme Linked ImmunoMagnetic Electrochemical assay (ELIME) was developed for the detection of the hepatitis A virus (HAV). This system is based on the use of new polydopamine-modified magnetic nanobeads as solid support for the immunochemical chain, and an array of 8 screen-printed electrodes as a sensing platform. Enzymatic-by-product is quickly measured by differential pulse voltammetry. For this purpose, all analytical parameters were optimized; in particular, different blocking reagents were evaluated in order to minimize the nonspecific interaction of bioreagents. Using the ELIME assays, a quantitative determination of HAV can be achieved with a detection limit of 1·10-11 IU mL-1 and a working range between 10-10 - 5 × 10-7 IU mL-1. The cross-reactivity of the commercial monoclonal antibodies against HAV used in ELIME assays was tested for Coxsackie B4, resulting very low. The sensitivity was also investigated and compared with spectrophotometric sandwich ELISA. The average relative standard deviation (RSD) of the ELIME method was less than 5% for the assays performed on the same day, and 7% for the measurements made on different days. The proposed system was applied to the cell culture of HAV, which title was quantified by Real-Time Quantitative Reverse Transcription PCR (RT¬qPCR). To compare the results, a correlation between the units used in ELIME (IU mL-1) and those used in RT¬qPCR (genome mL-1) was established using a HAV-positive sample, resulting in 1 IU mL-1-10-4 gen mL-1 (R2 = 0.978). The ELIME tool exhibits good stability and high biological selectivity for HAV antigen detection and was successfully applied for the determination of HAV in tap water.
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Carbon black nanoparticles to sense algae oxygen evolution for herbicides detection: Atrazine as a case study. Biosens Bioelectron 2020; 159:112203. [PMID: 32364935 DOI: 10.1016/j.bios.2020.112203] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/30/2020] [Accepted: 04/07/2020] [Indexed: 11/28/2022]
Abstract
A novel amperometric algae-based biosensor was developed for the detection of photosynthetic herbicides in river water. The green photosynthetic algae Chlamydomonas reinhardtii was immobilized on carbon black modified screen-printed electrodes, exploiting carbon black as smart nanomaterial to monitor changes in algae oxygen evolution during the photosynthetic process. The decrease of oxygen evolution, occurring in the presence of herbicides, results in a decrease of current signals by means of amperometric measurements, in an analyte concentration dependent manner. Atrazine as case study herbicide was detected in a concentration range of 0.1 and 50 μM, with a linear range from 0.1 to 5 μM and a detection limit of 1 nM. No interference was observed in presence of 100 ppb arsenic, 20 ppb copper, 5 ppb cadmium, 10 ppb lead, 10 ppb bisphenol A, and 1 ppb paraoxon, tested as safety limits. A ~25% matrix effect and satisfactory recovery values of 107 ± 10% and 96 ± 8% were obtained in river water for 3 and 5 μM of atrazine, respectively. Stability studies were also performed obtaining a high working stability up to 10 h and repeatability with an RSD of 1.1% (n = 12), as well as a good storage stability up to 3 weeks.
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An eco-designed paper-based algal biosensor for nanoformulated herbicide optical detection. JOURNAL OF HAZARDOUS MATERIALS 2019; 373:483-492. [PMID: 30947038 DOI: 10.1016/j.jhazmat.2019.03.082] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/20/2019] [Accepted: 03/18/2019] [Indexed: 05/23/2023]
Abstract
In this study we reported the development of a paper-based algal biosensor for the optical detection of nanoencapsulated-atrazine, a forefront nanoformulated herbicide with a high effective post-emergence herbicidal activity. In particular, the unicellular green photosynthetic algae Chlamydomonas reinhardtii was immobilised on a paper substrate soaked with an agar thin film and placed in a glass optical measurement cell, obtaining a totally environmental-friendly device. Nanoencapsulated-atrazine was detected by following the variable fluorescence (1-VJ) parameter, which decreased inversely proportional to the herbicide concentrations, in a range between 0.5 and 200 nM, indicating a linear relationship in the measured dose-response curves and a detection limit of 4 pM. Interference studies resulted in a very slight interference in presence of 2 ppm copper and 10 ppb arsenic at safety limits, as well as a slight matrix effect and a satisfactory recovery value of 96 ± 5% for 75 nM nanoencapsulated-atrazine in tap water. Stability studies were also performed obtaining a good storage stability up to 3 weeks. Results demonstrated the suitability of the proposed paper-based optical biosensor as a valid support in smart agriculture for on site, environmental friendly, cost effective and sensitive nanoencapsulated-atrazine analysis.
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Origami multiple paper-based electrochemical biosensors for pesticide detection. Biosens Bioelectron 2019; 126:346-354. [DOI: 10.1016/j.bios.2018.10.014] [Citation(s) in RCA: 159] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/23/2018] [Accepted: 10/09/2018] [Indexed: 12/14/2022]
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Iridium oxide (IV) nanoparticle-based electrocatalytic detection of PBDE. Biosens Bioelectron 2019; 127:150-154. [DOI: 10.1016/j.bios.2018.11.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 11/26/2018] [Accepted: 11/29/2018] [Indexed: 10/27/2022]
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How to extend range linearity in enzyme inhibition-based biosensing assays. Talanta 2018; 189:365-369. [DOI: 10.1016/j.talanta.2018.06.087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 12/11/2022]
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Disposable electrochemical immunosensor for cortisol determination in human saliva. Talanta 2018; 188:50-57. [DOI: 10.1016/j.talanta.2018.05.039] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 02/05/2023]
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Low-cost and reagent-free paper-based device to detect chloride ions in serum and sweat. Talanta 2018; 179:186-192. [DOI: 10.1016/j.talanta.2017.10.030] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/10/2017] [Accepted: 10/20/2017] [Indexed: 10/18/2022]
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Electrochemical Biosensors for Rapid Detection of Foodborne Salmonella: A Critical Overview. SENSORS 2017; 17:s17081910. [PMID: 28820458 PMCID: PMC5579882 DOI: 10.3390/s17081910] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/13/2017] [Accepted: 08/13/2017] [Indexed: 12/11/2022]
Abstract
Salmonella has represented the most common and primary cause of food poisoning in many countries for at least over 100 years. Its detection is still primarily based on traditional microbiological culture methods which are labor-intensive, extremely time consuming, and not suitable for testing a large number of samples. Accordingly, great efforts to develop rapid, sensitive and specific methods, easy to use, and suitable for multi-sample analysis, have been made and continue. Biosensor-based technology has all the potentialities to meet these requirements. In this paper, we review the features of the electrochemical immunosensors, genosensors, aptasensors and phagosensors developed in the last five years for Salmonella detection, focusing on the critical aspects of their application in food analysis.
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Fully integrated ready-to-use paper-based electrochemical biosensor to detect nerve agents. Biosens Bioelectron 2017; 93:46-51. [DOI: 10.1016/j.bios.2016.10.091] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/03/2016] [Accepted: 10/26/2016] [Indexed: 01/23/2023]
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ELIME assay vs Real-Time PCR and conventional culture method for an effective detection of Salmonella in fresh leafy green vegetables. Talanta 2017; 166:321-327. [PMID: 28213241 DOI: 10.1016/j.talanta.2017.01.071] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 11/27/2022]
Abstract
The detection of Salmonella according to EC regulation is still primarily based on traditional microbiological culture methods that may take several days to be completed. The purpose of this work is to demonstrate the applicability of an Enzyme-Linked-Immuno-Magnetic-Electrochemical (ELIME) assay, recently developed by our research group for the detection of salmonella in irrigation water, in fresh (raw and ready-to-eat) leafy green vegetables by comparison with Real-Time PCR (RTi-PCR) and ISO culture methods. Since vegetables represent a more complex matrix than irrigation water, preliminary experiments were carried out on two leafy green vegetables that resulted negative for salmonella by the ISO method. 25g of these samples were experimentally inoculated with 1-10 CFU of S. Napoli or S. Thompson and pre-enriched for 20h in two different broths. At this time aliquots were taken, concentrated at different levels by centrifugation, and analyzed by ELIME and RTi-PCR. Once selected the best culture medium for salmonella growth, and the optimal concentration factor suitable to reduce the sample matrix effect, enhancing the out-put signal, several raw and ready-to-eat leafy green vegetables were artificially inoculated and pre-enriched. Aliquots were then taken at different incubation times and analyzed with both techniques. Results obtained showed that 20 and 8h of pre-enrichment were required to allow the target salmonella (1-10 CFU/25g) to multiply until reaching a detectable concentration by ELIME and RTi-PCR assays, respectively. A confirmation with the ISO culture method was carried out. Based on the available literature, this is the first report of the application of an ELISA based method for the detection of Salmonella in vegetables.
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How cutting-edge technologies impact the design of electrochemical (bio)sensors for environmental analysis. A review. Anal Chim Acta 2017; 959:15-42. [PMID: 28159104 DOI: 10.1016/j.aca.2016.12.035] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 11/25/2022]
Abstract
Through the years, scientists have developed cutting-edge technologies to make (bio)sensors more convenient for environmental analytical purposes. Technological advancements in the fields of material science, rational design, microfluidics, and sensor printing, have radically shaped biosensor technology, which is even more evident in the continuous development of sensing systems for the monitoring of hazardous chemicals. These efforts will be crucial in solving some of the problems constraining biosensors to reach real environmental applications, such as continuous analyses in field by means of multi-analyte portable devices. This review (with 203 refs.) covers the progress between 2010 and 2015 in the field of technologies enabling biosensor applications in environmental analysis, including i) printing technology, ii) nanomaterial technology, iii) nanomotors, iv) biomimetic design, and (v) microfluidics. Next section describes futuristic cutting-edge technologies that are gaining momentum in recent years, which furnish highly innovative aspects to biosensing devices.
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Allosteric DNA nanoswitches for controlled release of a molecular cargo triggered by biological inputs. Chem Sci 2016; 8:914-920. [PMID: 28572901 PMCID: PMC5452262 DOI: 10.1039/c6sc03404g] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/03/2016] [Indexed: 12/14/2022] Open
Abstract
A rationally designed new class of DNA-based nanoswitches allosterically regulated by specific biological targets, antibodies and transcription factors, can load and release a molecular cargo in a controlled fashion.
Here we demonstrate the rational design of a new class of DNA-based nanoswitches which are allosterically regulated by specific biological targets, antibodies and transcription factors, and are able to load and release a molecular cargo (i.e. doxorubicin) in a controlled fashion. In our first model system we rationally designed a stem-loop DNA-nanoswitch that adopts two mutually exclusive conformations: a “Load” conformation containing a doxorubicin-intercalating domain and a “Release” conformation containing a duplex portion recognized by a specific transcription-factor (here Tata Binding Protein). The binding of the transcription factor pushes this conformational equilibrium towards the “Release” state thus leading to doxorubicin release from the nanoswitch. In our second model system we designed a similar stem-loop DNA-nanoswitch for which conformational change and subsequent doxorubicin release can be triggered by a specific antibody. Our approach augments the current tool kit of smart drug release mechanisms regulated by different biological inputs.
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Trends in the use of partial nephrectomy for cT1 renal tumors: Analysis of a 10-yr European multicenter dataset. Eur J Surg Oncol 2016; 42:1729-1735. [DOI: 10.1016/j.ejso.2016.03.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/07/2016] [Accepted: 03/21/2016] [Indexed: 11/16/2022] Open
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Fatty acids profiling reveals potential candidate markers of semen quality. Andrology 2016; 4:1094-1101. [DOI: 10.1111/andr.12236] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/12/2016] [Accepted: 05/17/2016] [Indexed: 01/29/2023]
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Screen-printed electrode modified with carbon black and chitosan: a novel platform for acetylcholinesterase biosensor development. Anal Bioanal Chem 2016; 408:7299-309. [DOI: 10.1007/s00216-016-9604-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/20/2016] [Accepted: 04/26/2016] [Indexed: 10/21/2022]
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21
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Electronic tongue for microcystin screening in waters. Biosens Bioelectron 2016; 80:154-160. [DOI: 10.1016/j.bios.2016.01.050] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/11/2016] [Accepted: 01/18/2016] [Indexed: 12/30/2022]
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22
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Novel reagentless paper-based screen-printed electrochemical sensor to detect phosphate. Anal Chim Acta 2016; 919:78-84. [DOI: 10.1016/j.aca.2016.03.011] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 02/29/2016] [Accepted: 03/07/2016] [Indexed: 01/31/2023]
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23
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Electrochemical biosensors based on nanomodified screen-printed electrodes: Recent applications in clinical analysis. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2016.01.032] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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24
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Rapid and label-free detection of ochratoxin A and aflatoxin B1 using an optical portable instrument. Talanta 2016; 150:440-8. [DOI: 10.1016/j.talanta.2015.12.048] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/09/2015] [Accepted: 12/14/2015] [Indexed: 11/17/2022]
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Commercially Available (Bio)sensors in the Agrifood Sector. BIOSENSORS FOR SUSTAINABLE FOOD - NEW OPPORTUNITIES AND TECHNICAL CHALLENGES 2016. [DOI: 10.1016/bs.coac.2016.04.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Development and evaluation of an ELIME assay to reveal the presence of Salmonella in irrigation water: Comparison with Real-Time PCR and the Standard Culture Method. Talanta 2015; 149:202-210. [PMID: 26717832 DOI: 10.1016/j.talanta.2015.11.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/29/2015] [Accepted: 11/04/2015] [Indexed: 11/15/2022]
Abstract
A reliable, low-cost and easy-to-use ELIME (Enzyme-Linked-Immuno-Magnetic-Electrochemical) assay for detection of Salmonella enterica in irrigation water is presented. Magnetic beads (MBs), coupled to a strip of eight-magnetized screen-printed electrodes localized at the bottom of eight wells (8-well/SPE strip), effectively supported a sandwich immunological chain. Enzymatic by-product is quickly measured by chronoamperometry, using a portable instrument. With the goal of developing a method able to detect a wide range of Salmonella serotypes, including S. Napoli and S. Thompson strains responsible for various community alerts, different kinds of MBs, antibodies and blocking agents were tested. The final system employs MBs coated with a broad reactivity monoclonal antibody anti-salmonella and blocked with dry milk. For a simple and rapid assay these two steps were performed in a preliminary phase, while the two sequential incubations for the immuno-recognition events were merged in a single step of 1h. In parallel a Real-Time PCR (RTi-PCR) method, based on a specific locked nucleic acid (LNA) fluorescent probe and an internal amplification control (IAC), was carried out. The selectivity of the ELIME and RTi-PCR assays was proved by inclusivity and exclusivity tests performed analyzing different Salmonella serotypes and non-target microorganisms, most commonly isolated from environmental sources. Furthermore, both methods were applied to experimentally and not experimentally contaminated irrigation water samples. Results confirmed by the ISO culture method, demonstrated the effectiveness of ELIME and RTi-PCR assays to detect a low number of salmonella cells (1-10 CFU/L) reducing drastically the long analysis time usually required to reveal this pathogen.
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Carbon black as successful screen-printed electrode modifier for phenolic compound detection. Electrochem commun 2015. [DOI: 10.1016/j.elecom.2015.08.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Screen-printed electrode modified with carbon black nanoparticles for phosphate detection by measuring the electroactive phosphomolybdate complex. Talanta 2015; 141:267-72. [DOI: 10.1016/j.talanta.2015.04.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/27/2015] [Accepted: 04/02/2015] [Indexed: 11/25/2022]
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A general approach to the design of allosteric, transcription factor-regulated DNAzymes. Chem Sci 2015; 6:3692-3696. [PMID: 28706715 PMCID: PMC5496187 DOI: 10.1039/c5sc00228a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/09/2015] [Indexed: 12/26/2022] Open
Abstract
Here we explore a general strategy for the rational design of nucleic acid catalysts that can be allosterically activated by specific nucleic-acid binding proteins. To demonstrate this we have combined a catalytic DNAzyme sequence and the consensus sequence recognized by specific transcription factors to create a construct exhibiting two low-energy conformations: a more stable conformation lacking catalytic activity and lacking the transcription factor binding site, and a less stable conformation that is both catalytically active and competent to bind the transcription factor. The presence of the target transcription factor pushes the equilibrium between these states towards the latter conformation, concomitantly activating catalysis. To demonstrate this we have designed and characterized two peroxidase-like DNAzymes whose activities are triggered upon binding either TATA binding protein or the microphthalmia-associated transcription factor. Our approach augments the current tool kit for the allosteric control of DNAzymes and ribozymes and, because transcription factors control many key biological functions, could have important clinical and diagnostic applications.
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Screen-Printed Electrodes Modified with Carbon Nanomaterials: A Comparison among Carbon Black, Carbon Nanotubes and Graphene. ELECTROANAL 2015. [DOI: 10.1002/elan.201500168] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Recent advances in biosensors based on enzyme inhibition. Biosens Bioelectron 2015; 76:180-94. [PMID: 26227311 DOI: 10.1016/j.bios.2015.07.010] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 06/28/2015] [Accepted: 07/05/2015] [Indexed: 02/07/2023]
Abstract
Enzyme inhibitors like drugs and pollutants are closely correlated to human and environmental health, thus their monitoring is of paramount importance in analytical chemistry. Enzymatic biosensors represent cost-effective, miniaturized and easy to use devices; particularly biosensors based on enzyme inhibition are useful analytical tools for fast screening and monitoring of inhibitors. The present review will highlight the research carried out in the last 9 years (2006-2014) on biosensors based on enzyme inhibition. We underpin the recent advances focused on the investigation in new theoretical approachs and in the evaluation of biosensor performances for reversible and irreversible inhibitors. The use of nanomaterials and microfluidic systems as well as the applications of the various biosensors in real samples is critically reviewed, demonstrating that such biosensors allow the development of useful devices for a fast and reliable alarm system.
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Phosphate Detection through a Cost-Effective Carbon Black Nanoparticle-Modified Screen-Printed Electrode Embedded in a Continuous Flow System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:7934-7939. [PMID: 26066782 DOI: 10.1021/acs.est.5b00218] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An automatable flow system for the continuous and long-term monitoring of the phosphate level has been developed using an amperometric detection method based on the use of a miniaturized sensor. This method is based on the monitoring of an electroactive complex obtained by the reaction between phosphate and molybdate that is consequently reduced at the electrode surface. The use of a screen-printed electrode modified with carbon black nanoparticles (CBNPs) leads to the quantification of the complex at low potential, because CBNPs are capable of electrocatalitically enhancing the phosphomolybdate complex reduction at +125 mV versus Ag/AgCl without fouling problems. The developed system also incorporates reagents and waste storage and is connected to a portable potentiostat for rapid detection and quantification of phosphate. Main analytical parameters, such as working potential, reagent concentration, type of cell, and flow rate, were evaluated and optimized. This system was characterized by a low detection limit (6 μM). Interference studies were carried out. Good recovery percentages comprised between 89 and 131.5% were achieved in different water sources, highlighting its suitability for field measurements.
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Microengine-assisted electrochemical measurements at printable sensor strips. Chem Commun (Camb) 2015; 51:8668-71. [DOI: 10.1039/c5cc02222c] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A new microengine-based built-in-platform exploiting a surprising dual action with solution mixing and control of the reaction parameters, has been applied for accelerating chemical reactions (organophosphorous nerve agents hydrolysis) and electrochemical detection of non-hazardous by-product (p-nitrophenol) using printable sensor strip.
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A prospective study to evaluate the efficacy of Cistiquer in improving lower urinary tract symptoms in females with urethral syndrome. MINERVA UROL NEFROL 2014; 66:225-232. [PMID: 25034330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
AIM The aim of the study was to compare Cistiquer, a new phytotherapeutic product developed for chronic bladder inflammatory diseases, and intra-vesical administration of gentamicin plus betametasone, in females with urethral syndrome. METHODS Between september 2013 and may 2014, 60 women with urethral syndrome and trigonitis were incuded in this study. Patients were randomly assigned to treatment with intra-vesical administration of betametasone 8 mg plus gentamicin 80 mg (group A), and oral administration of Cistiquer (group B) for 7 weeks. Before and after the therapeutic protocol, symptoms were assessed by three days voiding diary, the overactive bladder questionnaire short form and a ten points visual analogic scale adopted to assess the micturition discomfort. Histologic findings were assessed by the examination of specimens obtained by cold bladder biopsies of the bladder trigone at baseline in all the subjects. RESULTS The two groups had significant and comparable symptoms improvement. However, the score obtained from the visual analogic scale decreased significantly only in the group submitted to oral therapy. Furthermore, in the group treated with endovesical approach, higher drop out rate and higher incidence of urinary infection were observed. CONCLUSION Patients with urethral syndrome and trigonitis improved symptoms either with oral therapy with Cistiquer and with intra-vesical administration of gentamicin plus betametasone. However, treatment adherence resulted higher for patients treated by oral therapy and rate of adverse events resulted higher for those submitted to endovesical treatment.
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Screen-printed biosensor modified with carbon black nanoparticles for the determination of paraoxon based on the inhibition of butyrylcholinesterase. Mikrochim Acta 2014. [DOI: 10.1007/s00604-014-1370-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
BACKGROUND Archaeological bones contain only small amounts of DNA due to post-mortem DNA degradation and the changes endogenous DNA is subjected to during diagenesis. An important step before undertaking such time-consuming and costly analyses as ancient DNA investigation is to predict the presence of DNA in ancient samples. To date, the leading screening method has been amino acid racemization; however, other analytical techniques can also be used to assess the degree of bone preservation. AIM The aim of the present study was to relate the presence of DNA with bone preservation in order to select samples potentially suitable for ancient DNA analysis. SUBJECTS AND METHODS Bones collected from several archaeological sites, different locations (cave, rockshelter or sub divo) and diachronic periods were selected for analytical and spectroscopic analysis in order to correlate bone tissue preservation with the presence of DNA. Different techniques were combined to assess the degree of preservation of organic and inorganic components. RESULTS As determined by different analytical methods, preservation of the inorganic component was best associated with the presence of DNA. CONCLUSION Evaluation of the bone preservation state may be an efficient step to predict the presence of DNA in ancient samples prior to aDNA analysis.
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Development of a hydrogen peroxide sensor based on screen-printed electrodes modified with inkjet-printed Prussian blue nanoparticles. SENSORS 2014; 14:14222-34. [PMID: 25093348 PMCID: PMC4179063 DOI: 10.3390/s140814222] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 07/16/2014] [Accepted: 07/23/2014] [Indexed: 11/16/2022]
Abstract
A sensor for the simple and sensitive measurement of hydrogen peroxide has been developed which is based on screen printed electrodes (SPEs) modified with Prussian blue nanoparticles (PBNPs) deposited using piezoelectric inkjet printing. PBNP-modified SPEs were characterized using physical and electrochemical techniques to optimize the PBNP layer thickness and electroanalytical conditions for optimum measurement of hydrogen peroxide. Sensor optimization resulted in a limit of detection of 2 × 10(-7) M, a linear range from 0 to 4.5 mM and a sensitivity of 762 μA ∙ mM(-1) ∙ cm(-2) which was achieved using 20 layers of printed PBNPs. Sensors also demonstrated excellent reproducibility (<5% rsd).
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Severe obstructive sleep apnoea syndrome and erectile dysfunction: a prospective randomised study to compare sildenafil vs. nasal continuous positive airway pressure. Int J Clin Pract 2014; 68:995-1000. [PMID: 24852701 DOI: 10.1111/ijcp.12463] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND A high incidence of erectile dysfunction (ED) among patients with obstructive sleep apnoea syndrome (OSAS) has been reported, with a strong correlation between obstructive sleep apnoea, ED, and quality of life (QOL), and it has been estimated that 10-60% of patients with OSAS suffer from ED. In this prospective randomised controlled trial, we investigated 82 men with ED consecutively who were referred to the outpatient clinic for sleep disorders and had severe OSAS (AHI> 30 events/h) without any other comorbidities as a possible cause of ED. The aim of this study was to evaluate and compare the efficacy of sildenafil vs. continuous positive airway pressure (CPAP) in men with ED and severe OSAS. METHODS Eighty-two patients were randomised to two main treatment groups: group 1 patients (n = 41) were treated with 100-mg sildenafil 1 h before sexual intercourse without CPAP, and group 2 patients (n = 41 men) were treated with only nasal CPAP during night time sleep. Both groups were evaluated with the same questionnaires (International Index of Erectile Function-EF domain; Sex Encounter Profile; Erectile Dysfunction Inventory Treatment Satisfaction) 12 weeks after treatment. RESULTS In patients receiving sildenafil treatment, 58.2% of those who attempted sexual intercourses were successful compared to 30.4% in the CPAP group. The mean number of successful attempts per week was significantly higher in the sildenafil group compared with the CPAP group (2.9 vs. 1.7, respectively; p < 0.0001). The mean IIEF-EF domain scores were significantly higher in the sildenafil group compared with the CPAP group (p < 0.0001). The overall satisfaction rate was 68% with sildenafil treatment and 29% with CPAP treatment. CONCLUSIONS This study confirms that severe OSAS is strongly associated with erectile dysfunction. CPAP and sildenafil (100 mg) are safe and effective therapies for OSAS-related ED patients. In the present study sildenafil was more effective than CPAP in treating ED associated with OSAS, as indicated by a significantly higher rate of successful attempts at intercourse and higher IIEF-EF domain scores. Our study, to date, is the only that has investigated sildenafil in patients with severe OSAS.
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Development and validation of a multi-residue method for determination of 18 β-agonists in bovine urine by UPLC–MS/MS. Microchem J 2014. [DOI: 10.1016/j.microc.2014.02.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Stripping Analysis of As(III) by Means of Screen-Printed Electrodes Modified with Gold Nanoparticles and Carbon Black Nanocomposite. ELECTROANAL 2014. [DOI: 10.1002/elan.201400041] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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386 Urodynamics useless before surgery for female stress urinary incontinence: Are you sure? Results from a multicenter single nation database. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/s1569-9056(14)60381-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Rheoreversible hydrogels in paper restoration processes: a versatile tool. Chem Cent J 2014; 8:10. [PMID: 24513147 PMCID: PMC3926867 DOI: 10.1186/1752-153x-8-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 02/01/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Paper based artworks are probably ones of the most difficult materials to restore, because of their complexity and fragile structure. Cleaning of paper artifacts, one of the process commonly carried out during restoration, usually involves the use of solvents (organic or not), that may cause several troubles, like swelling and dissolution of some components, and may also be harmful to the users. RESULTS Innovative procedure for cleaning paper artworks is reported in this paper. It is based on the use of rheoreversible, biocompatible hydrogels containing poly(ethylene oxide) or poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) and α-cyclodextrin. We have studied two types of polymer with different hydrophobic properties in order to obtain two different hydrogels with slightly different cleaning capabilities. Our overall strategy has been to develop innovative systems based on these hydrogels so as to better confront the problems that a restorer faces during the cleaning of paper samples. Rheoreversible hydrogels are intriguing materials because their application and removal is not invasive and does not require a liquid treatment that could induce damage to the paper. CONCLUSIONS These hydrogels have been applied in the cleaning of both new and aged paper samples and their cleaning efficiency has been established. Moreover, by comparison with traditional methods, the greater efficacy of the proposed procedure has been demonstrated.To assess the cleaning efficacy of these hydrogels, a multidisciplinary approach, combining non-invasive spectroscopic infrared techniques together with scanning electron microscopy, chromatographic (HPLC) analysis and pH investigations has been used. Near infrared spectroscopy spectra were coupled with a chemometric analysis to achieve a better interpretation of data.This work constitutes a preliminary step towards focused study in the development of α-cyclodextrin/polymer hydrogel family which will allow cleaning of paper artifacts with peculiar characteristics.
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Does the neobladder filling modulate soleus H reflex? Clin Neurophysiol 2014; 125:425-7. [DOI: 10.1016/j.clinph.2013.06.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 06/21/2013] [Accepted: 06/23/2013] [Indexed: 11/15/2022]
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EP-1293: Computed tomography perfusion of prostate cancer before and after radiation therapy: Early experience results. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)31411-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Development of a QCM (Quartz Crystal Microbalance) Biosensor to Detection of Mycotoxins. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/978-3-319-00684-0_37] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Abstract
Here, we employ a model electrochemical DNA sensor to demonstrate that the detection limit and specificity of surface-based sensors often are not dependent on the true affinity of the probe for its target but are simply dependent on the effective probe concentration. Under these circumstances, the observed affinity (and thus the sensor's detection limit and specificity) will depend on the density with which the probes are packed on the surface of the sensor, the surface area, and even the volume of sample employed.
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Antimicrobial and biosensing ultrasound-responsive lysozyme-shelled microbubbles. ACS APPLIED MATERIALS & INTERFACES 2013; 5:464-471. [PMID: 23265433 DOI: 10.1021/am302660j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Air-filled lysozyme microbubbles (LSMBs) were engineered as a support for the immobilization of gold nanoparticles and an enzyme, alkaline phosphatase, in order to develop micro-antimicrobial and biosensing devices. Gold nanoparticles immobilized on LSMBs significantly improved the antimicrobial efficacy of the microbubbles against M. lysodeikticus. The surface functionalization of the microbubbles with gold nanoparticles did not affect their echogenicity when exposed to an ultrasound imaging probe. Alkaline phosphatase was conjugated on the surface of microbubbles without compromising its enzymatic activity. The functionalized microbubbles were used for the detection of paraoxon in aqueous solutions.
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Development of a QCM (Quartz Crystal Microbalance) Biosensor to the Detection of Aflatoxin B1. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojab.2013.24015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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