Mn-MOF catalyzed multi-site atom transfer radical polymerization electrochemical sensing of miRNA-21

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• MicroRNA-21 (miRNA-21) is a biomarker for various diseases.
• Traditional electrochemical biosensors often rely on toxic catalysts.
• Developing green and sensitive detection methods is crucial for early disease diagnosis.

Purpose of the Study:

• To develop a green electrochemical biosensor for quantifying miRNA-21.
• To utilize a metal-organic framework (MOF) as a catalyst for atom transfer radical polymerization (ATRP).
• To achieve ultrasensitive detection of miRNA-21 in biological samples.

Main Methods:

• Fabrication of an indium tin oxide (ITO) electrode modified with poly (diallyldimethylammonium chloride) (PDDA) and Mn-porous coordination network (Mn-PCN-222).
• Immobilization of aminated ssDNA (NH2-DNA) for miRNA-21 recognition.
• Initiation of ATRP using Fc-DNA@β-CD-Br15 and ferrocenylmethyl methacrylates (FcMMA) catalyzed by Mn-PCN-222.
• Electrochemical detection of the polymerized FcMMA signal.

Main Results:

• The developed biosensor demonstrated ultrasensitive detection of miRNA-21 with a detection limit of 0.4 fM.
• The Mn-PCN-222 MOF served as an effective green catalyst for ATRP.
• The biosensor successfully detected miRNA-21 in human serum samples.
• The electrochemical signal of FcMMA polymerization was distinct at ~0.33 V.

Conclusions:

• The MOF-catalyzed ATRP approach provides a sensitive and green platform for miRNA detection.
• This electrochemical biosensor shows significant potential for early clinical diagnosis of diseases associated with miRNA-21.
• The strategy highlights the utility of MOFs in developing advanced biosensing technologies.