Research On Synthesis And Sensing Properties Of Bimetallic PBA Nanocomposites

Prussian blue?PB?and Prussian blue analogues?PBA?,as a typical kind of metal organic framework?MOF?material,have catalytic,magnetic,optical and sensing properties,and have been applied in the fields of electrocatalysis,drug delivery,energy storage and biosensor.In this paper,several biosensors based on bimetallic PBA were designed to detect target analytes by calcining and compounding with other materials.Firstly,we designed and constructed a hollow bimetallic NiFe oxide-based aptamer sensor derived from NiFe PBA embedded in porous carbon to detect adenosine triphosphate?ATP?.Its series NiO_xFeO_y@mC materials were obtained by calcining hollow NiFe PBA at500,700 and 900?.The results show that the formed porous NiO_xFeO_y@mC composite calcinated at 900°C exhibited superior sensitivity toward ATP determination.The sensor not only has a low detection limit?LOD?of 0.98 fg·mL^-1,but also has high selectivity,good stability,repeatability and practicability.Secondly,we synthesized PBA nanospheres with novel core-shell heterostructures.AgNCs/Apt@CuFe@FeFe PBA nanocomposites were synthesized by using FeFe PB as the core,CuFe PBA as shell,bleomycin?BLM?targeting aptamers as template molecules,and AgNCs/Apt@CuFe@FeFe PBA nanocomposites were synthesized.Furthermore,aptamer sensors based on these materials were constructed to detect BLM.CuFe@FeFe PBA-based aptamer sensor LOD is 0.49 fg·mL^-1.AgNCs/Apt@CuFe@FeFe-based aptamer sensor LOD value is lower,0.0082 fg·mL^-1.At the same time,they also exhibit good selectivity,stability,repeatability and practicability.Finally,bimetallic CuCo PBA and graphene quantum dots?GQDs@CuCo PBA?were used to construct aptamer sensors for detection of various targets,including antibiotics?ochratoxin A,OTA?and tumor markers?epidermal growth factor receptor,EGFR?.The results of electrochemical detection showed that the LOD of GQDs@CuCo PBA-based aptamer sensors OTA and EGFR were very low,5.2 fg·mL^-1 and 0.42 fg·mL^-1,respectively.They could also be used for direct detection of cancer cells,MCF-7.In this study,a new idea of preparing PBA nanocomposites and their derivatives and constructing electrochemical biosensors with these materials were proposed,which further expanded the potential application of PBA materials.