scispace - formally typeset
Search or ask a question
Author

Ana P.M. Tavares

Bio: Ana P.M. Tavares is an academic researcher from University of Coimbra. The author has contributed to research in topics: Biosensor & Molecularly imprinted polymer. The author has an hindex of 8, co-authored 18 publications receiving 192 citations. Previous affiliations of Ana P.M. Tavares include International Student Exchange Programs & University of Minho.

Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, a novel device for monitoring chloramphenicol (CAP) on-site is described, making use of commercial carbon screen-printed electrodes (C-SPEs) modified with a suitable sensing element.
Abstract: A novel device for monitoring chloramphenicol (CAP) on-site is described, making use of commercial carbon screen-printed electrodes (C-SPEs) modified with a suitable sensing element. This element consisted of a molecularly imprinted polymer (MIP), produced in-situ, by electro-polymerization. The monomers used herein were Eriochrome black T (EBT), and polymerization was conducted in acetonitrile. Raman spectroscopy followed the chemical changes occurring at each stage of the carbon surface modification. The device performance was assessed by evaluating the changes in electron transfer properties of a standard redox probe [Fe(CN)6]3−/[Fe(CN)6]4− by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV). SWV and EIS electrochemical techniques were used to calibrate the system, having standard solutions prepared under different background media (electrolyte or water coming from a home fish tank). A wide linear range was observed, with linear responses of current/resistance against log (CAP concentration) down to 10 nM. Overall, the results obtained revealed that all modifications carried out on the sensing element were effective. The final sensor provided reproducible and accurate readings and was all assembled in-situ, in a very simple and straightforward approach, most likely suitable for scaling-up, directing towards its subsequent commercial use.

55 citations

Journal ArticleDOI
TL;DR: The results showed the development of a direct and facile sensor with good reproducibility, stability, sensitivity and more importantly, selectivity that may allow a premature assessment of cancer disease, thereby improving diagnosis, prognostics and survival rates.
Abstract: This work presents a cost-effective, label-free in point-of-care (POC) biosensor for the sensitive detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG), the most abundant oxidative product of DNA, that may allow a premature assessment of cancer disease, thereby improving diagnosis, prognostics and survival rates. The device targets the direct detection of 8-OHdG by using for the first time a carbon-ink 3-electrode on a paper substrate coupled to Differential Pulse Voltammetry readings. This design was optimized by adding nanostructured carbon materials to the ink and the conducting polymer PEDOT, enhancing the electrocatalytic properties of the sensor towards 8-OHdG detection. Meanwhile, the ability of this oxidative stress biomarker to undertake an oxidation reaction enabled the development of the sensing electrochemical device without the need of chemical probes and long incubation periods. This paper-modified sensor presented high electrochemical performance on the oxidation of 8-OHdG with a wide linear range (50-1000 ng/ml) and a low detection limit (14.4 ng/ml). Thus, our results showed the development of a direct and facile sensor with good reproducibility, stability, sensitivity and more importantly, selectivity. The proposed carbon-based electrochemical sensor is a potential candidate to be miniaturized to small portable size, which make it applicable for in-situ 8-OHdG sensing in real biological samples.

52 citations

Journal ArticleDOI
TL;DR: The results obtained evidenced the possibility of using a DMFC as a transducing element in an electrochemical sensor, confirming the sensitive and selective readings of the bio (sensing) imprinted film.

43 citations

DOI
29 Oct 2021
TL;DR: Paper-based devices and platforms targeting SARS-CoV-2 are showcased and discussed, as a means to achieve quick and low-cost PoC diagnosis, including detection methodologies for viral genomic material, viral antigen detection, and serological antibody testing.
Abstract: The appearance and quick spread of the new severe acute respiratory syndrome coronavirus disease, COVID-19, brought major societal challenges. Importantly, suitable medical diagnosis procedures and smooth clinical management of the disease are an emergent need, which must be anchored on novel diagnostic methods and devices. Novel molecular diagnostic tools relying on nucleic acid amplification testing have emerged globally and are the current gold standard in COVID-19 diagnosis. However, the need for widespread testing methodologies for fast, effective testing in multiple epidemiological scenarios remains a crucial step in the fight against the COVID-19 pandemic. Biosensors have previously shown the potential for cost-effective and accessible diagnostics, finding applications in settings where conventional, laboratorial techniques may not be readily employed. Paper- and cellulose-based biosensors can be particularly relevant in pandemic times, for the renewability, possibility of mass production with sustainable methodologies, and safe environmental disposal. In this review, paper-based devices and platforms targeting SARS-CoV-2 are showcased and discussed, as a means to achieve quick and low-cost PoC diagnosis, including detection methodologies for viral genomic material, viral antigen detection, and serological antibody testing. Devices targeting inflammatory markers relevant for COVID-19 are also discussed, as fast, reliable bedside diagnostic tools for patient treatment and follow-up.

28 citations

Journal ArticleDOI
TL;DR: The findings demonstrate the applicability of the ICF framework and classification system for determining eligibility for special education services on the basis of student functioning rather than medical or psychological diagnose.
Abstract: Purpose: The International Classification of Functioning, Disability and Health (ICF) was introduced in Portuguese education law as the compulsory system to guide eligibility policy and practice in special education. This paper describes the implementation of the ICF and its utility in the assessment process and eligibility determination of students for special education.Methods: A study to evaluate the utility of the ICF was commissioned by the Portuguese Ministry of Education and carried out by an external evaluation team. A document analysis was made of the assessment and eligibility processes of 237 students, selected from a nationally representative sample.Results: The results provided support for the use of the ICF in student assessment and in the multidimensional approach of generating student functioning profiles as the basis for determining eligibility. The use of the ICF contributed to the differentiation of eligible and non eligible students based on their functioning profiles.Conclusions: The ...

26 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: A brief introduction to the electrochemical biosensors is presented, with the detailed discussion on recent trends in the development and applications of electrochemical neurotransmitter sensors based on CPs and their composites.

264 citations

Journal ArticleDOI
TL;DR: A review of the recent trends in potentiometric biosensors can be found in this article, where the authors provide an outlook of the potentiometrics based on the integration of ion-selective electrodes (ISEs) with new materials and emerging techniques.
Abstract: Potentiometry based on ion-selective electrodes (ISEs) has been injected with new vigor and gone through a renaissance with the improvements in the detection limits and selectivities of ISEs, the introduction of new materials, new sensing concepts (from conventional potentiometry to dynamic electrochemistry approaches), and deeper theoretical understanding and modelling of the potentiometric responses of ISEs. The new breakthroughs encourage innovations in ion sensing and biosensing applications. Moreover, with the introduction of new bioreceptors, such as enzymes, antibodies, aptamers, peptides, versatile sensing protocols have been designed for a broad range of different target molecules by using ISEs as powerful transducers. This paper reviews the recent trends in potentiometric biosensors. Their applications in biosensing of metal ions, small molecules, DNA, proteins, bacteria and toxicities have been discussed. This review provides the outlook of the potentiometric biosensing based on the integration of potentiometric ISEs with new materials and emerging techniques.

152 citations

Journal ArticleDOI
04 Jan 2018
TL;DR: The purpose of this review paper is to summarize the recently developed sensing techniques with the focus on neurotransmitters as the target analyte, and to discuss the outlook of simultaneous detection of multiple neurotransmitter species.
Abstract: Neurotransmitters are chemicals that act as messengers in the synaptic transmission process. They are essential for human health and any imbalance in their activities can cause serious mental disorders such as Parkinson’s disease, schizophrenia, and Alzheimer’s disease. Hence, monitoring the concentrations of various neurotransmitters is of great importance in studying and diagnosing such mental illnesses. Recently, many researchers have explored the use of unique materials for developing biosensors for both in vivo and ex vivo neurotransmitter detection. A combination of nanomaterials, polymers, and biomolecules were incorporated to implement such sensor devices. For in vivo detection, electrochemical sensing has been commonly applied, with fast-scan cyclic voltammetry being the most promising technique to date, due to the advantages such as easy miniaturization, simple device architecture, and high sensitivity. However, the main challenges for in vivo electrochemical neurotransmitter sensors are limited target selectivity, large background signal and noise, and device fouling and degradation over time. Therefore, achieving simultaneous detection of multiple neurotransmitters in real time with long-term stability remains the focus of research. The purpose of this review paper is to summarize the recently developed sensing techniques with the focus on neurotransmitters as the target analyte, and to discuss the outlook of simultaneous detection of multiple neurotransmitter species. This paper is organized as follows: firstly, the common materials used for developing neurotransmitter sensors are discussed. Secondly, several sensor surface modification approaches to enhance sensing performance are reviewed. Finally, we discuss recent developments in the simultaneous detection capability of multiple neurotransmitters.

141 citations

Journal ArticleDOI
TL;DR: The present brief review surveys novel achievements in the field of MIP nanostructures and their application for determination of protein analytes.

136 citations

Journal ArticleDOI
TL;DR: The progress in functionalization of cellulose papers with antibodies, nucleic acids and nanomaterials in PBBs and μPADs, is discussed and critically evaluated.

131 citations