Ana Rita Cardoso

Scopus Publications

Enzyme-Free Monitoring of Glucose Using Molecularly Imprinted Polymers and Gold Nanoparticles
Ana Rita Aires Cardoso, Pedro Miguel Cândido Barquinha, Maria Goreti Ferreira Sales
Biosensors, 2025
This work describes a non-enzymatic electrochemical glucose biosensor combining for the first time molecularly imprinted polymers (MIPs) for glucose concentration and gold nanoparticles (AuNPs) on screen-printed carbon electrodes (SPEs), where both MIPs and AuNPs were assembled in situ. Electrochemical impedance spectroscopy (EIS) was used to evaluate the analytical performance of the sensor, which has a linear range between 1.0 µM and 1.0 mM when standard solutions are prepared in buffer. Direct measurement of glucose was performed by chronoamperometry, measuring the oxidation current generated during direct glucose oxidation. The selectivity was tested against ascorbic acid and the results confirmed a selective discrimination of the electrode for glucose. Overall, the work presented here represents a promising tool for tracking glucose levels in serum. The use of glucose MIP on the electrode surface allows the concentration of glucose, resulting in lower detection limits, and the use of AuNPs reduces the potential required for the oxidation of glucose, which increases selectivity. In addition, this possible combination of two analytical measurements following different theoretical concepts can contribute to the accuracy of the analytical measurements. This combination can also be extended to other biomolecules that can be electrochemically oxidised at lower potentials.
Ultrasound-assisted protein-enhanced graphene synthesis for rapid electrochemical antibody sensing
A. R. Cardoso, A. Suleimenova, João F.M. Alves, M. F. Frasco, Pedro Barquinha, M.Goreti F. Sales
Microchemical Journal, 2025
Electrochemical sensing poses challenges due to its intricate assembly requirements. Herein, our innovative approach simplifies the process, by utilizing graphene sheets exfoliated with ultrasound and stabilized by the same biorecognition element to be employed. This pioneering method offers exceptional analytical performance and both simplicity, and opens doors to a novel way to assemble biosensors for antibody monitoring • A new and simple approach for biographene production and direct use in electrochemical sensing of antibodies. • Using ultrasound from graphite exfoliation and graphene production in aqueous medium. • Using the biorecognition element to intercalate graphene sheets and stabilize them. • Application of this biographene to the electrochemical detection of antibodies. This study presents a novel method for the fabrication of graphene as a functional interface for electrochemical sensors. Graphene was synthesised by probe-assisted ultrasonic exfoliation of graphite stabilised by the SARS-CoV-2 spike (S) protein. In this dual-function approach, the S protein is used for both graphene stabilisation and antibody recognition, simplifying the production of biosensors. The biosensor was fabricated by modifying a carbon working electrode with the stabilised graphene-S-protein complex. Electrochemical impedance spectroscopy (EIS) revealed a linear detection range from 1.0 pg/mL to 10.0 ng/mL in diluted human serum, with a detection limit of 0.17 pg/mL. The high selectivity for the S protein was confirmed against the SARS-CoV-2 nucleocapsid (N) protein. The device successfully analysed serum samples, demonstrating its practical application. These results emphasise a simple, innovative platform that integrates graphene synthesis and biosensor functionality. This approach not only ensures a sensitive and stable substrate for monitoring antibodies against SARS-CoV-2, but also offers an approach that can be extended to detect different antibodies, by selecting the stabilising protein that binds to the intended antibody.
α-Synuclein plastic antibody applied to monitor monomeric structures and discriminate aggregated forms in human CSF
Inês S. da Silva, Ana R. Cardoso, Lasse Reimer, Annekatrin König, Christoph van Riesen, Tiago Fleming Outeiro, Poul Henning Jensen, M. Goreti F. Sales
Biosensors and Bioelectronics, 2025
Aggregation of alpha-synuclein (aSyn) occurs in presynaptic neurons and constitutes a key factor for the progression of Parkinson's disease, emphasising the urgency of early detection to support effective treatment. Unfortunately, a reliable, sensitive and cost-effective diagnostic tool has so far been lacking. Thus, this work presents a novel biosensor for detecting aSyn using plastic antibodies coupled to electrochemical detection. This biosensor was designed for portability and compatibility with point-of-care devices and exploits the electropolymerization of methylene blue (MB) together with aSyn on the carbon working electrode of screen-printed electrodes (SPEs). By electrochemical impedance spectroscopy (EIS) measurements, the sensor showed exceptional analytical performance in detecting aSyn monomers in human CSF samples. It showed a linear trend of response from 1 fM to 10 pM with an impressively low limit of detection of 69 aM. Selectivity tests confirmed the predominant response to aSyn monomers, a less intense response to oligomers and insensitivity to fibrils. Overall, this plastic antibody-based electrochemical sensor represents a significant breakthrough as it is the first of its kind to accurately, sensitively and selectively detect aSyn monomers with a partial response to oligomers. Its simplicity and reproducibility promise to contribute to the early and effective diagnosis of Parkinson's disease.
Biomimetic strategies for biosensing
Ana R. Cardoso, Liliana P.T. Carneiro, Akmaral Suleimenova, Manuela F. Frasco, M. Goreti F. Sales
Nature Derived Sensors Basic Principles and Recent Advances, 2025
Electrochemical biosensor-based detection assays for early diagnosis of neurodegenerative disorders
Inês S. da Silva, Ana R. Cardoso, M. Goreti F. Sales
Smart Diagnostics for Neurodegenerative Disorders Neuro Sensors, 2023
An ultra-sensitive electrochemical biosensor using the Spike protein for capturing antibodies against SARS-CoV-2 in point-of-care
Ana R. Cardoso, João Frederico Alves, Manuela F. Frasco, Ana Margarida Piloto, Verónica Serrano, Daniela Mateus, Ana Isabel Sebastião, Ana Miguel Matos, Anália Carmo, Teresa Cruz, Elvira Fortunato, M. Goreti F. Sales
Materials Today Bio, 2022
This work presents an innovative ultra-sensitive biosensor having the Spike protein on carbon-based screen-printed electrodes (SPEs), for monitoring in point-of-care antibodies against SARS-CoV-2, a very important tool for epidemiological monitoring of COVID-19 infection and establishing vaccination schemes. In an innovative and simple approach, a highly conductive support is combined with the direct adsorption of Spike protein to enable an extensive antibody capture. The high conductivity was ensured by using carboxylated carbon nanotubes on the carbon electrode, by means of a simple and quick approach, which also increased the surface area. These were then modified with EDC/NHS chemistry to produce an amine layer and undergo Spike protein adsorption, to generate a stable layer capable of capturing the antibodies against SARS-CoV-2 in serum with great sensitivity. Electrochemical impedance spectroscopy was used to evaluate the analytical performance of this biosensor in serum. It displayed a linear response between 1.0 pg/mL and 10 ng/mL, with a detection limit of ∼0.7 pg/mL. The analysis of human positive sera containing antibody in a wide range of concentrations yielded accurate data, correlating well with the reference method. It also offered the unique ability of discriminating antibody concentrations in sera below 2.3 μg/mL, the lowest value detected by the commercial method. In addition, a proof-of-concept study was performed by labelling anti-IgG antibodies with quantum dots to explore a new electrochemical readout based on the signal generated upon binding to the anti-S protein antibodies recognised on the surface of the biosensor. Overall, the alternative serologic assay presented is a promising tool for assessing protective immunity to SARS-CoV-2 and a potential guide for revaccination.
Carbon Electrodes with Gold Nanoparticles for the Electrochemical Detection of miRNA 21-5p
Verónica Morgado Serrano, Inês Simões Patrício Silva, Ana Rita Cardoso, Maria Goreti Ferreira Sales
Chemosensors, 2022
Extracellular vesicles are involved in many physiological and pathological activities. They transport miRNAs to recipient cells during their role in intercellular communication, making them emerging biomarkers of many diseases. Interest in exosomal miRNAs has grown after they have shown numerous advantages as biomarkers for diagnosis, prognosis, and evaluation of cancer treatment. This work describes the development of a biosensor for the detection of 21-5p miRNA in human serum using screen-printed carbon electrodes modified with gold nanoparticles fabricated in situ, an innovative approach to avoid the use of more expensive gold substrates that provide better analytical outputs. The several variables involved in the assembly of the biosensor were optimized by univariant mode. Under the best conditions, the biosensor showed a linear response from 0.010 fM to 10 pM, with a limit of detection (LOD) of 4.31 aM. The sensitivity was 0.3718 relative Ω per decade concentration in buffered saline solutions, and the standard deviation of the blank is 2.94 Ω. A linear response was also obtained when human serum samples were tested with miRNA 21-5p. Interference from similar miRNA and miss-match miRNA sequences was evaluated and good selectivity for miRNA 21-5p was observed. Overall, the device proposed is an alternative approach to gold substrates, which typically result in more sensitive systems and lower LODs, which compares favorably to current gold-based biosensors for the targeted miRNA. This design may be further extended to other nucleic acids.
Breaking the classics: Next-generation biosensors for the isolation, profiling and detection of extracellular vesicles
Raquel Vaz, Verónica M. Serrano, Yuselis Castaño-Guerrero, Ana R. Cardoso, Manuela F. Frasco, M. Goreti F. Sales
Biosensors and Bioelectronics X, 2022
Extracellular vesicles (EVs) contain biomarkers that may represent a paradigm shift in timely disease diagnosis and personalized therapeutic approaches. Despite tremendous progress in this field, the considerable complexity and heterogeneity of EVs, combined with hurdles in isolation and accurate characterization, have delayed their envisioned clinical translation. At the same time, emerging biosensor technologies are trying to overcome the limitations and provide new momentum to EVs research. In this review, the focus is given on the variety of novel approaches to improve the capture of EVs of interest from a myriad of sample types in terms of yield, purity, sensitivity, and specificity. These biosensing devices also contribute to the understanding of the content of EVs in correlation with their function. Given the pivotal role of EVs uncovered to date and the recent technological advances discussed herein, nanosensing platforms offer low-cost, fast, simple, and accurate methods that are likely to help gain more insight into the biology of EVs. Moreover, the prospect of identifying new roles and patterns will reinforce the importance of EVs and intercellular communication in health status.
Paper-Based Biosensors for COVID-19: A Review of Innovative Tools for Controlling the Pandemic
Tomás Pinheiro, A. Rita Cardoso, Cristina E. A. Sousa, Ana C. Marques, Ana P. M. Tavares, Ana Miguel Matos, Maria Teresa Cruz, Felismina T. C. Moreira, Rodrigo Martins, Elvira Fortunato, M. Goreti F. Sales
ACS Omega, 2021
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.
Employing bacteria machinery for antibiotic detection: Using DNA gyrase for ciprofloxacin detection
Ana R. Cardoso, Liliana P.T. Carneiro, Gustavo Cabral-Miranda, Martin F. Bachmann, M. Goreti F. Sales
Chemical Engineering Journal, 2021
This work describes a new successful approach for designing biosensors that detect antibiotics. It makes use of a biomimetic strategy, by employing the biochemical target of a given antibiotic as its biorecognition element. This principle was tested herein for quinolones, which target DNA gyrase in bacteria. Ciprofloxacin (CIPRO) was tested as a representative antibiotic from the quinolone group; the sensitivity of biosensor to this group was confirmed by checking the response to another quinolone antibiotic (norfloxacin, NOR) and to a non-quinolone antibiotic (ampicillin, AMP). The biorecognition element used was DNA gyrase attached by ionic interactions to a carbon support, on a working electrode on common screen-printed electrodes (SPEs). The response against antibiotics was tested for increasing concentrations of CIPRO, NOR or AMP, and following the subsequent electrical changes by electrochemical impedance spectroscopy. The DNAgyrase biosensor showed sensitive responses for CIPRO and NOR, for concentrations down to 3.02 nM and 30.2 nM, respectively, with a very wide response range for CRIPRO, up to 30.2 µM. Its response was also confirmed selective for quinolones, when compared to its response against AMP. Further comparison to an immunosensor of similar design (adding antibodies instead of DNA gyrase) was made, revealing favourable features for the new biomimetic biosensor with 1.52 nM of limit of detection (LOD). Overall, the new approach presented herein is simple and effective for antibiotic detection, displaying a selective response against a given antibiotic group. The use of bacterial machinery as biorecognition element in biosensors may also provide a valuable tool to study the mechanism of action in bacterial cells of new drugs. This is especially important in the development of new drugs to fight bacterial resistance.
Molecular imprinting on nanozymes for sensing applications
Ana R. Cardoso, Manuela F. Frasco, Verónica Serrano, Elvira Fortunato, Maria Goreti Ferreira Sales
Biosensors, 2021
In-situ production of Histamine-imprinted polymeric materials for electrochemical monitoring of fish
Verónica M. Serrano, Ana R. Cardoso, Mário Diniz, M. Goreti F. Sales
Sensors and Actuators B Chemical, 2020
Laser-Induced Graphene-Based Platforms for Dual Biorecognition of Molecules
Ana C. Marques, Ana R. Cardoso, Rodrigo Martins, M. Goreti F. Sales, Elvira Fortunato
ACS Applied Nano Materials, 2020
Non-enzymatic lab-on-paper devices for biosensing applications
Ana Carolina Marques, Tomás Pinheiro, Gabriela Vieira Martins, Ana Rita Cardoso, Rodrigo Martins, Maria Goreti Sales, Elvira Fortunato
Comprehensive Analytical Chemistry, 2020
An impedimetric molecularly-imprinted biosensor for Interleukin-1β determination, prepared by in-situ electropolymerization on carbon screen-printed electrodes
Ana R. Cardoso, M.H. de Sá, M. Goreti F. Sales
Bioelectrochemistry, 2019
Molecularly-imprinted chloramphenicol sensor with laser-induced graphene electrodes
Ana R. Cardoso, Ana C. Marques, Lídia Santos, Alexandre F. Carvalho, Florinda M. Costa, Rodrigo Martins, M. Goreti F. Sales, Elvira Fortunato
Biosensors and Bioelectronics, 2019
Biosensor-based selective detection of Zika virus specific antibodies in infected individuals
Gustavo Cabral-Miranda, Ana R. Cardoso, Luis C.S. Ferreira, M. Goreti F. Sales, Martin F. Bachmann
Biosensors and Bioelectronics, 2018
In-situ generated molecularly imprinted material for chloramphenicol electrochemical sensing in waters down to the nanomolar level
Ana R. Cardoso, Ana P.M. Tavares, M. Goreti F. Sales
Sensors and Actuators B Chemical, 2018
Detecting circulating antibodies by controlled surface modification with specific target proteins: Application to malaria
Ana R. Cardoso, Gustavo Cabral-Miranda, Arturo Reyes-Sandoval, Martin F. Bachmann, M. Goreti F. Sales
Biosensors and Bioelectronics, 2017
Artificial receptors for the electrochemical detection of bacterial flagellar filaments from Proteus mirabilis
M. Azizur R. Khan, Ana Rita Aires Cardoso, M. Goreti F. Sales, Susana Merino, Juan M. Tomás, F. Xavier Rius, Jordi Riu
Sensors and Actuators B Chemical, 2017
Novel and simple electrochemical biosensor monitoring attomolar levels of miRNA-155 in breast cancer
Ana R. Cardoso, Felismina T.C. Moreira, Rúben Fernandes, M. Goreti F. Sales
Biosensors and Bioelectronics, 2016