Partially reduced graphene oxide as highly efficient DNA nanoprobe

Area of Science:

• Biomaterials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Graphene oxide (GO) is widely used in biosensing.
• Understanding GO-DNA interactions is crucial for developing sensitive detection methods.
• Existing GO-based DNA sensors have limitations in sensitivity and background noise.

Purpose of the Study:

• To investigate the impact of reduction degree on graphene oxide (GO)-DNA interactions.
• To explore the fluorescence quenching mechanism in GO-DNA systems.
• To develop a highly sensitive and efficient nanoprobe for DNA detection.

Main Methods:

• Synthesis of partially reduced graphene oxide (pRGO) via a mild alkaline reduction method.
• Characterization of pRGO water-dispersibility and sp(2) carbon bond restoration.
• Investigation of fluorescence quenching of DNA upon interaction with GO and pRGO.
• Determination of binding constants to quantify pRGO-ssDNA affinity.
• Development of a homogeneous DNA sensing strategy using pRGO.

Main Results:

• pRGO maintains good water-dispersibility.
• Fluorescence quenching efficiency increases with the degree of sp(2) carbon bond restoration in pRGO.
• The quenching mechanism is identified as static quenching.
• pRGO exhibits significantly stronger binding affinity with ssDNA compared to GO.
• The developed pRGO-based nanoprobe achieves a low limit of detection (50 pM) without amplification.

Conclusions:

• The reduction degree of graphene oxide critically influences its interaction with DNA.
• Partially reduced graphene oxide (pRGO) serves as a superior platform for DNA sensing compared to pristine GO.
• The proposed pRGO-based strategy offers advantages in terms of low nanoprobe dosage, reduced background, rapid response, and enhanced sensitivity for homogeneous DNA detection.