Abstract
Simultaneous and point-of-care detection of multiple protein biomarkers has significant impact on patient care. Spinal Muscular Atrophy (SMA), Cystic Fibrosis (CF) and Duchenne Muscular Dystrophy (DMD) are well known progressive hereditary disorders associated with increased morbidity as well as mortality. Therefore, rapid detection of biomarkers specific for these three disorders in newborns offers new opportunities for early diagnosis, delaying symptoms and effective treatment. Here, we report the development of a disposable carbon nanofiber (CNF)-based electrochemical immunosensor for simultaneous detection of survival motor neuron 1 (SMN1), cystic fibrosis transmembrane conductance regulator (CFTR) and DMD proteins. The CNF-modified array electrodes were first functionalized by electroreduction of carboxyphenyl diazonium salt. Then, the immunosensor was fabricated by the covalent immobilization of the three antibodies on the working electrodes of the array sensor via carbodiimide (EDC/NHS) chemistry. Simultaneous detection of CFTR, DMD and SMN1 was achieved with high sensitivity and detection limits of 0.9 pg/ml, 0.7 pg/ml and 0.74 pg/ml, respectively. The multiplexed immunosensor has also shown strong selectivity against non-specific proteins. Moreover, high recovery percentage was obtained when the immunosensor was applied in spiked whole blood samples. This voltammetric immunosensor offers cost effective, easy to use, rapid and high throughput potential screening method for these three hereditary disorders using only few drops of blood.