# From Biomarkers to Biosensors: Transforming Comorbidity Management in Dialysis Care

## TL;DR

This paper reviews new biosensor technologies that could improve the monitoring of comorbid conditions in dialysis patients by continuously tracking key biomarkers.

## Contribution

The paper provides a critical assessment of emerging biosensors for dialysis biomarkers with a focus on continuous monitoring and minimally invasive sampling.

## Key findings

- New biosensors based on electrochemistry, optics, and nanophotonics show promise for detecting dialysis biomarkers.
- Microneedle- and microtube-based sampling systems are being developed for long-term biomarker monitoring.
- Current biosensors face challenges like biofouling and calibration drift, but future developments could enable proactive comorbidity management.

## Abstract

Patients receiving dialysis treatments suffer from a high rate of systemic comorbid conditions, including cardiovascular disease, mineral and bone disorders, chronic inflammation, amyloidosis, and recurring infections, leading to increased morbidity and mortality rates despite the progress made in the field of renal replacement therapies. The aforementioned conditions result from the continued dysregulation and overproduction of molecular biomarkers, which cannot be adequately monitored by traditional, intermittent laboratory tests. This review critically assesses the newly developed biosensor technologies for the detection of major dialysis biomarkers, including potassium, phosphorus, parathyroid hormone (PTH), β2-microglobulin, creatinine, and cystatin C, with special emphasis on biosensors based on electrochemistry, optics, impedimetry, nanophotonics, and biological engineering techniques. These recent biosensors have been evaluated based on their analytical performance, the biofluids used in the studies, and their suitability for measuring relevant concentrations of these biomarkers. Special attention is given to biosensors capable of continuous operation or minimally invasive sampling, as well as to newly developed biofluid sampling techniques, including microneedle-, microtube-, and micropillar-based systems, for the long-term monitoring of the biomarkers in the serum of patients receiving dialysis treatments. The biosensing techniques for measuring infection biomarkers have also been discussed, given the high risk of bloodstream and access infections among patients receiving dialysis. The limitations of these biosensors include biofouling, calibration drift, and their integration into the dialysis treatment workflow. Finally, the future prospects of the recent biosensors offer the possibility of the proactive management of the high rate of comorbid conditions in this high-risk population of patients receiving dialysis treatments.