Smartphone as a Portable Detector, Analytical Device, or Instrument Interface

The Encyclopedia Britannia defines a smartphone as a mobile telephone with a display screen, at the same time serves as a pocket watch, calendar, addresses book and calculator and uses its own operating system (OS). A smartphone is considered as a mobile telephone integrated to a handheld computer. As the market matured, solid-state computer memory and integrated circuits became less expensive over the following decade, smartphone became more computer-like, and more more-advanced services, and became ubiquitous with the introduction of mobile phone networks. The communication takes place for sending and receiving photographs, music, video clips, e-mails and more. The growing capabilities of handheld devices and transmission protocols have enabled a growing number of applications. The integration of camera, access Wi-Fi, payments, augmented reality or the global position system (GPS) are features that have been used for science because the users of smartphone have risen all over the world. This chapter deals with the importance of one of the most common communication channels, the smartphone and how it impregnates in the science. The technological characteristics of this device make it a useful tool in social sciences, medicine, chemistry, detections of contaminants, pesticides, drugs or others, like so detection of signals or image

Detection of ochratoxin A in aptamer assay using total internal reflection ellipsometry

The current work is a continuation of our research targeted the development of novel optical sensing technologies for detection of mycotoxins. The method of (TIRE) was developed in the last decade as a combination of spectroscopic ellisometry and SPR and was proved to be a highly sensitive analytical tool in bio-sensing particularly attractive for detection of low molecular weight analytes, such as mycotoxins. The use of aptamers as highly specific artificial molecular receptors to ochratoxin A (OTA) in conjunction with the method Total Internal Reflection Ellipsometry (TIRE) is reported here for the first time. Our results showed a possibility of label-free optical detection of OTA down to 0.01 ppb in concentration in direct assay with specific aptamer. The kinetics of aptamer/OTA binding was studied with dynamic TIRE spectral measurements and allowed evaluating the affinity constant KD = 1.8 10−8 Mol which is characteristic for highly specific aptamer/OTA binding. © 201

Label-free optical detection of mycotoxins using specific aptamers immobilized on gold nanostructures.

This work focuses on the development of the novel label-free optical apta-sensors for detection of mycotoxins. A highly sensitive analytical method of total internal reflection ellipsometry (TIRE) combined with Localized Surface Plasmon Resonance (LSPR) phenomenon in nano-structured gold films was exploited here for the first time for detection of aflatoxin B1 and M1 in direct assay with specific aptamers immobilized on the surface of gold. The achieved detection of low molecular weight molecules, such as aflatoxin B1 and M1, in a wide range of concentrations from 100 ng/mL down to 0.01 ng/mL is remarkable for the LSPR method. The study of binding kinetics of aflatoxin molecules to their respective aptamers using dynamic TIRE measurements yielded the values of affinity constants in the range of 10 ⁻10 mol, which is characteristic for highly specific aptamer/target interactions similar to that for monoclonal antibodies. The effect of aptamers' DNA chain length on their binding characteristics was analyzed

Marine biotoxins in the Catalan littoral: could biosensors be integrated into monitoring programmes?

Aquest article descriu els sensors enzimàtics i immunosensors electroquímics que s'han desenvolupat als nostres grups per a la detecció de la biotoxina marina àcid okadaic (OA), i discuteix la possibilitat d'integrar-los en programes de seguiment. Els sensors enzimàtics per a OA que es presenten es basen en la inhibició de la proteïna fosfatasa (PP2A) per aquesta toxina i la mesura electroquímica de l'activitat enzimàtica mitjançant l'ús de substrats enzimàtics apropiats, electroquímicament actius després de la seva desfosforació per l'enzim. Els immunosensors electroquímics descrits en aquest article es basen en un enzimoimmunoassaig sobre fase sòlida competitiu indirecte (ciELISA), amb fosfatasa alcalina (ALP) o peroxidasa (HRP) com a marcatges, i un sistema de reciclatge enzimàtic amb diaforasa (DI). Els biosensors presentats aquí s'han aplicat a l'anàlisi de dinoflagel·lats, musclos i ostres. Les validacions preliminars amb assaigs colorimètrics i LC-MS/MS han demostrat la possibilitat d'utilitzar les bioeines desenvolupades per al cribratge preliminar de biotoxines marines en mostres de camp o de cultiu, que ofereixen informació complementària a la cromatografia. En conclusió, tot i que encara cal optimitzar alguns paràmetres experimentals, la integració dels biosensors a programes de seguiment és viable i podria proporcionar avantatges respecte a altres tècniques analítiques pel que fa al temps d'anàlisi, la simplicitat, la selectivitat, la sensibilitat, el fet de poder ser d'un sol ús i l'efectivitat de cost.This article describes the electrochemical enzyme sensors and immunosensors that have been developed by our groups for the detection of marine biotoxin okadaic acid (OA), and discusses the possibility of integrating them into monitoring programmes. The enzyme sensors for OA reported herein are based on the inhibition of immobilised protein phosphatase 2A (PP2A) by this toxin and the electrochemical measurement of the enzyme activity through the use of appropriate enzyme substrates, which are electrochemically active after dephosphorylation by the enzyme. The electrochemical immunosensors described in this article are based on a competitive indirect Enzyme- Linked ImmunoSorbent Assay (ciELISA), using alkaline phosphatase (ALP) or horseradish peroxidase (HRP) as labels, and an enzymatic recycling system with diaphorase (DI). The biosensors presented herein have been applied to the analysis of dinoflagellates, mussels and oysters. Preliminary validations with colorimetric assays and LC-MS/MS have demonstrated the possibility of using the developed biotools for the preliminary screening of marine biotoxins in field or cultured samples, offering complementary information to chromatography. In conclusion, although optimisation of some experimental parameters is still required, the integration of biosensors into monitoring programmes is viable and may provide advantages over other analytical techniques in terms of analysis time, simplicity, selectivity, sensitivity, disposability of electrodes and cost effectiveness

Label free aptasensor for lysozyme detection : a comparison of the analytical performance of two aptamers

This work presents a comparison of two different aptamers (COX and TRAN) for the detection of the ubiquitous protein lysozyme using aptamer-based biosensors. The detection is based on the specific recognition by the aptamer immobilized on screen printed carbon electrodes (SPCEs) via diazonium coupling reaction. The quantitative detection of lysozyme protein was achieved by electrochemical impedance spectroscopy (EIS). Very good linear ranges and detection limits for the lysozyme detection were obtained, from 0.025 to 1 μM and 725nM using aptamer COX and from 0.025 to 1 μM and 31.7nM using aptamer TRAN. The obtained results showed that the developed aptasensors exhibit good specificity, stability and reproducibility for lysozyme detection. The aptasensors were also tested in wine samples; very good recovery rates were obtained in the range from 96.4 to 102% for lysozyme detection. The recovery rates confirm the reliability and suitability of the developed method in wine matrix. The developed method could be a useful and promising platform for detection of lysozyme in different applications

Phenolic Composition, Antioxidant Capacity and Antiproliferative Activity of Ten Exotic Amazonian fruit

The socioeconomic, cultural, therapeutic, and nutritional potential of Amazonian fruits has been limited due to the scarce information about its phytochemical profile. The aim of this study was to determine the total phenolic content profiles by Folin colorimetric miniaturized assay, the identification of phenolic compounds by UHPLC-HRMS, the antioxidant capacity by DPPH, ABTS, and NBT assays, as well as, the antiproliferative activity by sulforhodamine B assay of extracts obtained from ten native fruits to the Amazon region, some of these consumed especially by indigenous population. A strong positive correlation between the content of total phenolic compounds and antioxidant capacity was demonstrated. The antiproliferative activities against Caco-2 cell line didn't necessarily be associated with a high antioxidant capacity and the total phenolic concentration, possibly, qualitative and quantitative differences in phenolic composition of these fruits influenced the antiproliferative activities. This research presented, for the first time, important characteristics of Amazon exotic fruits

Phenobarbital enhanced genotoxicity of ochratoxin A

Phenobarbital enhanced genotoxicity of ochratoxin