An electrochemical biosensor to detect anti-asparaginase antibodies using immobilized ASNase on carbon-printed electrodes

Acute lymphoblastic leukaemia (ALL) is one of the most common types of childhood cancer. Treatment of ALL may involve using the enzyme L-asparaginase (ASNase) from Escherichia coli as the first option. However, native E. coli ASNase can induce the production of antibodies, interfering with its pharmacological activity and increasing the risk of allergic reactions. Therefore, monitoring the production of anti-ASNase antibodies in patients is essential for determining treatment efficacy. Hence, a simple, precise, and selective method for the measurement of antibodies is of great interest. In this context, this work reports on an electrochemical biosensor based on carbon-printed electrodes to quantify antibodies in ALL patients under treatment using an ASNase-based protocol. For selective detection of anti-ASNase antibodies, ASNase was immobilized on electrodes using the nanocomposite Fe₃O₄/chitosan. The biosensor showed linearity for the antibody concentrations between 0.1 and 10 µg mL⁻¹, with a limit of detection of 150 ng L⁻¹. In addition, the biosensor was selective and provided reproducible results with a variability of 3.3%. From these results, it was concluded that the biosensor presented here is a promising device for the measurement of anti-ASNase antibodies produced in patients under treatment for ALL.

Graphical abstract