Development of a novel voltammetric aptasensor for highly sensitive detection of cardiac troponin I, utilizing ciprofloxacin-loaded UIO-66 metal-organic frameworks.

Acute myocardial infarction (AMI) has been recognized as a leading cause of death, posing a significant threat to human health for decades. The assessment of cardiac troponin I (cTnI), an important biomarker for AMI, has demonstrated superior sensitivity and specificity in diagnosing myocardial damage. This research aims to establish a particularly sensitive and inexpensive electrochemical aptasensor for cTnI detection. The biosensing system was constructed utilizing a custom-made cell featuring a gold (Au) substrate, which exploits an innovative signal amplification approach involving ciprofloxacin (Cip) loaded into UIO-66 metal-organic framework (MOF). The measurement of the electrochemical oxidation current of released Cip molecules that is proportional to cTnI concentrations was accomplished with the differential pulse voltammetry (DPV) technique. The developed aptasensor exhibited an extremely low detection limit of 2.05 aM and a wide dynamic range, spanning from 3.14 aM to 314.0 pM. Additionally, the successful determination of cTnI in the presence of other blood proteins, such as myoglobin, human serum albumin (HSA), hemoglobin, and immunoglobulin G (IgG), demonstrates the high selectivity of the developed aptasensor. Moreover, in vitro studies of serum samples from patients with cardiac injury and healthy individuals demonstrated the aptasensor's capability in detecting cTnI at ultra-low concentrations, which could facilitate the early detection of cardiac injury.