An impedimetric immunosensor for the selective detection of CD34+ T-cells in human serum

Chimeric antigen receptor T (CAR-T) cell therapy has led to a paradigm change in cancer treatment. To allow widespread use of this therapy, it is important to reduce the costs associated with cells manufacturing whilst ensuring a high-quality production. Online biosensors can help monitor in real time the effectiveness of engineering CAR-T cells, with the possibility to be integrated on the workflow without the need to extract samples for off line analysis that require specialised personnel and expensive analytical equipment. In this context, we present an innovative label-free impedimetric immunosensor for the detection of CD34 ⁺ T-cells in human serum. The sensor is based on screen-printed gold electrodes functionalised with anti-CD34 antibody, via a mixed self-assembled monolayer of 11-mercaptoundecanoic acid and 6-mercapto-1-hexanol, which recognizes the CD34 antigen expressed onto the T-cells surfaces. The immunosensor exhibits a high selectivity and a wide working range in human serum, both in Faradaic and non-Faradaic detection conditions, being respectively of 230 – 1.4 × 10 ³ cell mL ⁻¹ and 50 – 1 × 10 ⁵ cell mL ⁻¹. This result, along with performance validation both in batch and flow-through operations, demonstrates the applicability of the developed immunosensor for clinical use.