Simultaneous electrochemical immunosensing of relevant cytokines to diagnose and track cancer and autoimmune diseases.

This work reports the first dual magnetic beads (MBs) assisted immunoplatform for the simultaneous determination of BAFF (B cell activation factor) and APRIL (a proliferation-induced ligand), two cytokines related to immunity and tumour invasion, growth and metastasis. The electrochemical immunoplatform involves sandwich-type immunoassays implemented on magnetic microparticles functionalized with neutravidin (NA-MBs) or carboxylic groups (HOOC-MBs), and amperometric detection (Eapp =  - 0.20 V vs. Ag pseudo-reference electrode) at screen-printed dual carbon electrodes (SPdCE) using the H2O2/hydroquinone (HQ) system. The developed immunosensors provide improved sensitivity, with LOD values of 0.33 and 16.4 pg mL-1 for BAFF and APRIL, respectively, and much shorter assay time that those claimed for ELISA kits and allow their simultaneous determination. The dual immunosensor permits discrimination between healthy individuals and patients diagnosed with Systemic Lupus Erythematosus (SLE) or colorectal cancer (CRC) through the determination of both cytokines in 100-times diluted human sera with results in agreement with those provided by the individual ELISA methodologies.

Enlightening the advancements in electrochemical bioanalysis for the diagnosis of Alzheimer's disease and other neurodegenerative disorders.

Neurodegenerative disorders (NDD), and particularly Alzheimer's disease (AD), are one of the greatest challenges facing our current medicine and society because of its increasing incidence and the high burden imposed both on patients' families and health systems. Despite this, their accurate diagnosis, mostly conducted by cerebrospinal fluid (CSF) analysis or neuroimaging techniques, costly, time-consuming, and unaffordable for most of the population, remains a complex task. In this situation, electrochemical biosensors are flourishing as promising alternative tools for the simple, fast, and low-cost diagnosis of NDD/AD. This review article provides the relevant clinical details of NDD/AD along with the closely related genetic (genetic mutations, polymorphisms of ApoE and specific miRNAs) and proteomic (amyloid-ß peptides, total and phosphorylated tau protein) biomarkers circulating mostly in CSF. In addition, the article systematically enlightens a general view of the electrochemical affinity biosensors (mostly aptasensors and immunosensors) reported in the past two years for the determination of such biomarkers. The different developed strategies, analytical performances and applications are comprehensively discussed. Recent advancements in signal amplification methodologies involving smart designs and the use of nanomaterials and rational surface chemistries, as well as the challenges that must be struggled and the prospects in electrochemical affinity biosensing to bring more accessibility to NDD/AD diagnosis, prognosis, and follow-up, are also pointed out.