Structure-adaptive dual-function poly-T sequences enable a homogeneous label-free colorimetric sensing platform

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• Research on G-rich nucleic acids is extensive, but the catalytic properties of T-rich sequences remain underexplored.
• Poly-thymine (poly-T) sequences are typically viewed for their structural roles, not catalytic functions.

Purpose of the Study:

• To investigate the peroxidase-like activity of poly-T sequences.
• To develop a novel homogeneous colorimetric sensing platform for melamine detection using poly-T sequences.

Main Methods:

• Investigated the peroxidase-like activity of poly-T sequences with acetic acid as an activator.
• Constructed a homogeneous colorimetric sensing platform utilizing long-chain poly-T sequences to catalyze the TMB-H2O2 reaction.
• Utilized the formation of T-melamine-T structures to induce conformational changes and suppress catalytic activity.

Main Results:

• Poly-T sequences exhibit peroxidase-like activity, with efficiency increasing with sequence length.
• The developed sensing platform successfully detects melamine.
• Melamine binding to poly-T sequences leads to structural changes that significantly inhibit the catalytic activity.

Conclusions:

• Poly-T sequences possess inherent catalytic properties, acting as activatable peroxidase mimics.
• A novel, dual-function ssDNA sensing platform integrates catalytic and recognition capabilities for melamine detection.
• The structure-dependent activity modulation of poly-T sequences allows for rapid, on-site detection via a colorimetric assay.