Aptamer-Embedded Zirconium-Based Metal–Organic Framework Composites Prepared by De Novo Bio-Inspired Approach with Enhanced Biosensing for Detecting Trace Analytes

A series
of Zr-based metal–organic framework (MOF) composites
embedded with three kinds of aptamer strands (509-MOF@Apt) were achieved
by a one-step de novo synthetic approach. A platform for ultrasensitive
detection of analytes, namely, thrombin, kanamycin, and carcinoembryonic
antigen (CEA), was also established. Considering the conformational
changes caused by the binding interactions between aptamer strands
and targeted molecules, the label-free electrochemical aptasensors
based on 509-MOF@Apt composites could be developed to detect various
target molecules. By comparing the common fabrication approaches of
aptasensors, a distinct determination mechanism was presented through
analysis of the electrochemical measurements on different interaction
behaviors between probe aptamer strands and 509-MOF materials. The
optimized aptasensors based on 509-MOFs@Apt demonstrated excellent
sensitivity (with the detection limit of 0.40, 0.37, and 0.21 pg mL–1 for CEA, thrombin, and kanamycin, respectively),
stability, repeatability, and applicability. This work will provide
a new platform for direct and feasible detection in biosensing related
to clinical diagnostics and therapeutics, and further, extend the
scope of potential applications for MOF materials.