In the orthopaedic surgery eld, the use of medical implants to treat a patient’s bone fracture is nowadays a

common practice, nevertheless, it is associated with possible cases of infection. The consequent hardware

infection can lead to implant failure and systemic infections, with prolonged hospitalization, time-consum-

ing rehabilitation treatments, and extended antibiotic therapy. Hardware infections are strictly related to bac-

terial adhesion to the implant, leading to infection occurrence and consequent pH decreasing from physio-

logical level to acid pH. Here, we demonstrate the new strategy to use an orthopaedic implant functiona-

lized with iridium oxide lm as the working electrode for the potentiometric monitoring of pH in hardware

infection diagnosis. A functional investigation was focused on selecting the implant material, namely tita-

nium, titanium alloy, and stainless steel, and the component, namely screws and implants. After selecting

the titanium-based implant as the working electrode and a silver wire as the reference electrode in the nal

con guration of the smart sensing orthopaedic implant, a calibration curve was performed in standard solu-

tions. An equation equal to y = (0.76 ± 0.02)− (0.068 ± 0.002) x, R2 = 0.996, was obtained in the pH range

of 4–8. Subsequently, hysteresis, interference, matrix e ect, recovery study, and storage stability were inves-

tigated to test the overall performance of the sensing device, demonstrating the tremendous potential of

electrochemical sensors to deliver the next generation of smart orthopaedic implants.