In thisstudy, anultrasensitive electrochemical aptasensor for the determination oftheβ-casomorphin 7(BCM-7) as a promising biomarker of autism disorder is introduced. According to the proposed strategy, a glassy carbon electrode (GCE) was modified by thiourea capped-ZnS QDs (ZnS-QDs) and gold nanoparticles (AuNPs) to further immobilization the amino-aptamer (NH2-Apt) on its surface. The NH2-Apt as a receptor of the BCM-7 was attached to the embedded surface via a formation of the Au–N bonds between the AuNPs and amino groups of the Apt. The evaluation of aptasensor by various electrochemical techniques exhibited successful sensing of the BCM-7 under twobroadlinear concentration ranges from1fM to0.6μMwitha limit ofdetection (LOD) down to 350aM. Also, the performance of the aptasensor in BCM-7 detection in real human urine samples was satisfactorily investigated. These findings may facilitate distinguish of this challenging disorder and help human health.
