Trimetallic signal amplification aptasensor for TSP-1 detection based on Ce-MOF@Au and AuPtRu nanocomposites

In this work, an aptamer was used as the target capturing agent and a trimetallic signal amplification strategy based on Ce-MOF@Au and AuPtRu NPs was demonstrated for the sensitive detection of TSP-1. Herein, the synthesized AuPtRu nanocomposite (AuPtRu NPs) not only acts as the catalyst for catalyzing hydrogen peroxide but also acts as a nanocarrier for capturing the -NH₂ termination single strand DNA (S1) to obtain the signal probe (SP, AuPtRu nanocomposite/S1). Then, SP was efficiently linked into TSP-1 aptamers with the addition of complementary linking strands to form M1 (SP/aptamer). The Ce-MOF@Au nanocomposites were obtained by in situ reduction and used as GCE electrode modification materials. The -NH₂-modified capture probe (CP) DNA was immobilized on the surface of Ce-MOF@Au nanocomposites for hybridizing SP. In the presence of the target TSP-1, the aptamer recognizes the target and binds strongly so that SP is released from the prepared M1 and then hybridized with CP. When the detection solution contains an electrochemical matrix of H₂O₂, AuPtRu NPs can oxidize H₂O₂ to obtain an enhanced signal. Furthermore, the proposed aptasensor has a very low LOD of 0.13 fg mL^-1 TSP-1 in the detection range of 1 fg mL^-1 to 10 ng mL^-1. Moreover, the proposed platform also has application implications for other potential targets.