Capabilities - The Parolo Lab

The Parolo Lab combines clinical samples, molecular engineering and sensing technologies to develop diagnostic systems around real analytical and clinical needs. These capabilities can be used independently or integrated across the complete diagnostic-development workflow.

Biomarkers, Clinical Samples & Sample Handling

Starting from the right biomarker — and the right sample.

We work with clinically relevant samples and cohorts to identify, evaluate and prioritize biomarkers according to the diagnostic or prognostic question being addressed. This includes both host- and pathogen-derived targets and the study of their behaviour across disease stages, patient populations and biological matrices.

Sample handling is considered part of the sensing problem from the beginning. We investigate strategies for processing complex samples, reducing matrix interference, and concentrating or enriching low-abundance targets. Approaches include magnetic capture, affinity-based enrichment and sample-preparation strategies designed for integration with decentralized diagnostic systems.

Most relevant works

Pedreira-Rincón J, Balerdi-Sarasola L, Villanueva G, et al., Parolo C. pLDH to identify severity in imported malaria: Implementing smartphone video analysis for rapid clinical decision-making. Biosensors and Bioelectronics (2026) 294, 118228. DOI: 10.1016/j.bios.2025.118228

Cambra-Pellejà M, Aguilar R, Vidal M, et al., Dobaño C, Parolo C, Gandasegui J. NIE Antigen Mapping for Serological Diagnostic of Strongyloidiasis. ACS Infectious Diseases (2026). DOI: 10.1021/acsinfecdis.6c00271

Balerdi-Sarasola L, Parolo C, Fleitas PE, et al., Camprubí-Ferrer D. Host biomarkers for early identification of severe imported Plasmodium falciparum malaria. Travel Medicine and Infectious Disease (2023) 54, 102608. DOI: 10.1016/j.tmaid.2023.102608

Molecular Recognition & Bioreceptor Engineering

Molecular Recognition & Bioreceptor Engineering

We select and engineer bioreceptors according to the requirements of each application, working with antibodies, aptamers and nucleic-acid-based recognition systems. Our activities range from bioreceptor selection and characterization to aptamer development through SELEX and the integration of recognition elements into different sensing architectures.

We are particularly interested in programmable molecular recognition. DNA structures and sequence-defined interactions can be used to control proximity, displacement, competition and conformational change, allowing recognition events to be coupled directly to signal generation and enabling analytical properties such as sensitivity, selectivity and dynamic range to be deliberately engineered.

Most relevant works

Yang Q, Pedreira-Rincón J, Balerdi-Sarasola L, et al., Parolo C. An aptamer-based electrochemical sensor for the quantification of the malaria biomarker lactate dehydrogenase. Biosensors and Bioelectronics (2025) 274, 117152. DOI: 10.1016/j.bios.2025.117152

Parolo C, Idili A, Ortega G, et al., Plaxco KW. Real-time monitoring of a protein biomarker. ACS Sensors (2020) 5, 1877–1881. DOI: 10.1021/acssensors.0c01085

Parolo C, Greenwood AS, Ogden NE, et al., Plaxco KW. E-DNA scaffold sensors and the reagentless, single-step measurement of HIV-diagnostic antibodies in human serum. Microsystems & Nanoengineering (2020) 6, 13. DOI: 10.1038/s41378-019-0119-5

Lateral-Flow & Paper Diagnostics

Portable, low-cost diagnostics for point-of-care and decentralized testing.

Lateral-flow assays and paper-based diagnostics are a central technology of the Parolo Lab. We design assay architectures around the intended application, from bioreceptor immobilization and nanoparticle conjugation to membrane selection, fluid transport, reaction kinetics and signal generation.

Our research includes sandwich and competitive assays, strategies for improving sensitivity and quantitative performance, paper-based sample processing and integration with portable or smartphone-based readout. Particular attention is given to robustness, ease of use, storage and manufacturing constraints, allowing analytical performance to be considered together with the requirements of decentralized and point-of-care testing.

Most relevant works

Parolo C, Sena-Torralba A, Bergua JF, et al., Merkoçi A. Tutorial: design and fabrication of nanoparticle-based lateral-flow immunoassays. Nature Protocols (2020) 15, 3788–3816. DOI: 10.1038/s41596-020-0357-x

Sena-Torralba A, Torné-Morató H, Parolo C, et al., Merkoçi A. A Novel Ratiometric Fluorescent Approach for the Modulation of the Dynamic Range of Lateral Flow Immunoassays. Advanced Materials Technologies (2022) 7, 2101450. DOI: 10.1002/admt.202101450

Parolo C, de la Escosura-Muñiz A, Merkoçi A. Enhanced lateral flow immunoassay using gold nanoparticles loaded with enzymes. Biosensors and Bioelectronics (2013) 40, 412–416. DOI: 10.1016/j.bios.2012.06.049

Electrochemical Biosensing & Continuous Monitoring

Sensitive molecular measurements from portable devices to real-time monitoring.

We develop electrochemical biosensors that translate molecular recognition directly into electrical signals, enabling sensitive measurements with compact instrumentation and small sample volumes. Our work includes surface-functionalized electrodes, DNA-based sensing architectures and electrochemical approaches compatible with portable and decentralized analysis.

A particularly important direction is electrochemical aptamer-based (E-AB) sensing for real-time and continuous molecular monitoring. Conformational changes induced by target binding can modulate electrochemical signalling without requiring additional reagents, creating opportunities to follow changes in biomarker concentrations dynamically rather than obtaining only a single measurement. We investigate the molecular design, surface chemistry and sensing architectures needed to bring these approaches toward biologically and clinically relevant applications.

Most relevant works

Parolo C, Idili A, Ortega G, et al., Plaxco KW. Real-time monitoring of a protein biomarker. ACS Sensors (2020) 5, 1877–1881. DOI: 10.1021/acssensors.0c01085

Idili A, Parolo C, Álvarez-Diduk R, Merkoçi A. Rapid and Efficient Detection of the SARS-CoV-2 Spike Protein Using an Electrochemical Aptamer-Based Sensor. ACS Sensors (2021) 6, 3093–3101. DOI: 10.1021/acssensors.1c01222

Nanomaterials & Signal Engineering

Boosting sensitivity and tuning analytical performance through engineered signal generation.

We use nanomaterials and engineered signal-generation mechanisms to control how molecular recognition is converted into a measurable response. Our work includes nanoparticle synthesis and functionalization, bioconjugation strategies and the integration of nanomaterials into paper-based, optical and electrochemical assays.

Rather than using nanomaterials as labels alone, we investigate how their optical, catalytic and surface properties can improve sensitivity, tune dynamic range or enable new readout mechanisms. Signal amplification and transduction are therefore designed together with bioreceptor chemistry and assay architecture to match the analytical requirements of each application.

Most relevant works

Chamorro-Garcia A, Parolo C, Ortega G, et al., Plaxco KW. The sequestration mechanism as a generalizable approach to improve the sensitivity of biosensors and bioassays. Chemical Science (2022) 13, 12219–12228. DOI: 10.1039/D2SC03901J

Sena-Torralba A, Ba Ngo D, Parolo C, et al., Merkoçi A. Lateral flow assay modified with time-delay wax barriers as a sensitivity and signal enhancement strategy. Biosensors and Bioelectronics (2020) 168, 112559. DOI: 10.1016/j.bios.2020.112559

Usability, Readout & Digital Integration

Ensuring diagnostic technologies can be used, interpreted and acted upon in real-world settings.

A diagnostic system must ultimately provide information that users can obtain, interpret and act upon. We therefore study the interaction between sensing technology, readout and the context in which a diagnostic test will be used.

Our work includes usability studies, portable optical and electrochemical readers, smartphone-based image and video analysis, quantitative signal interpretation and integration with digital-health tools. Through activities connected to GHIS and FAMBA, we also explore how diagnostic information can be linked with digital-health and telemedicine systems to support interpretation, follow-up and decision-making. These studies help determine whether technologies developed under controlled conditions can be implemented effectively in clinical, decentralized and field settings.

Most relevant works

Menéndez-Valladares P, Delgado RM, Núñez-Jurado D, et al., Montaner J. Smartphone-Enabled Point-of-Care Testing for Prehospital Stroke Diagnosis. Prehospital Emergency Care (2024), 1–10. DOI: 10.1080/10903127.2024.2437657

Miller BS, Parolo C, Turbé V, et al., McKendry RA. Quantifying Biomolecular Binding Constants using Video Paper Analytical Devices. Chemistry – A European Journal (2018) 24, 9783–9787. DOI: 10.1002/chem.201802394