Multiplexed and amplified electrochemical aptasensor for sensitive assay of piperaquine and mefloquine

Simultaneous detection and quantification of antimalarial drugs is important for evaluating the spread of their resistance. On the base of the target-induced assembly of branched DNA nanostructure signal amplification and different electrochemical coding tags at distinct potentials, an aptasensing method for multiplexed and highly sensitive detection of piperaquine (PQ) and mefloquine (MQ) antimalarial drugs is established. The target drugs associate with and switch the conformation of the aptamers to release free ssDNA trigger sequences, which initiate the self-assembly of many methylene blue (MB)- and ferrocene (Fc)-labeled auxiliary signal sequences to form branched nano-assemblies on electrode. The electrode-captured MB and Fc tags thus yield highly magnified current reponses at well-resolved potentials for simultaneously monitoring PQ and MQ with respective detection limits as low as 0.061 ng mL −1 (i.e., 0.114 nM) and 0.17 ng mL −1 (i.e., 0.449 nM). Moreover, the simultaneous detection of PQ and MQ in diluted human serum samples has also been verified by the developed sensor, revealing its potential for multiplexed monitoring of different drugs in connection with the corresponding aptamers for various application purposes.