Easily Multiplexable Immunoplatform to Assist Heart Failure Diagnosis through Amperometric Determination of Galectin‐3

Paper electrochemical immunosensor for the rapid screening of Galectin-3 patients with heart failure

A paper electrochemical immunosensor for the combined binding and quantification of the heart failure (HF) biomarker Galectin-3 has been developed. The simple design of the new sensor is comprised of paper material that is decorated with gold nanostructures, to maximize its electroactive surface area, and functionalized with target-specific recognition molecules to selectively bind the protein from aqueous solutions. The binding of the protein caused the blockage of the electron flow to the sensor electroactive surface, thus causing its oxidation potential to shift and the corresponding current to reduce quantitatively with the increase in the protein concentration within the working range of 0.5ng/mL-8ng/mL (LOQ-0.5 ng/mL). This novel sensor was able to quantify Galectin-3 concentration in saliva samples from HF patients and healthy controls within 20 min with good reproducibility (RSD = 3.64%), without the need for complex sample processing steps. The electrochemical measurements of the patient samples were cross validated by ELISA where the percent agreement between the two methods was found to be 92.7% (RSD = 7.20%). Therefore, the new paper immunosensor sensor has a strong potential for rapid and cost-effective screening of the Galectin 3 biomarker at points of care, thus supporting the timely diagnosis of heart failure.

Electroanalytical point-of-care detection of gold standard and emerging cardiac biomarkers for stratification and monitoring in intensive care medicine - a review

Determination of specific cardiac biomarkers (CBs) during the diagnosis and management of adverse cardiovascular events such as acute myocardial infarction (AMI) has become commonplace in emergency department (ED), cardiology and many other ward settings. Cardiac troponins (cTnT and cTnI) and natriuretic peptides (BNP and NT-pro-BNP) are the preferred biomarkers in clinical practice for the diagnostic workup of AMI, acute coronary syndrome (ACS) and other types of myocardial ischaemia and heart failure (HF), while the roles and possible clinical applications of several other potential biomarkers continue to be evaluated and are the subject of several comprehensive reviews. The requirement for rapid, repeated testing of a small number of CBs in ED and cardiology patients has led to the development of point-of-care (PoC) technology to circumvent the need for remote and lengthy testing procedures in the hospital pathology laboratories. Electroanalytical sensing platforms have the potential to meet these requirements. This review aims firstly to reflect on the potential benefits of rapid CB testing in critically ill patients, a very distinct cohort of patients with deranged baseline levels of CBs. We summarise their source and clinical relevance and are the first to report the required analytical ranges for such technology to be of value in this patient cohort. Secondly, we review the current electrochemical approaches, including its sub-variants such as photoelectrochemical and electrochemiluminescence, for the determination  of important CBs highlighting the various strategies used, namely the use of micro- and nanomaterials, to maximise the sensitivities and selectivities of such approaches. Finally, we consider the challenges that must be overcome to allow for the commercialisation of this technology and transition into intensive care medicine.