Confining Carbon Dots in Porous Wood: The Singlet Oxygen Enhancement Strategy for Photothermal Signal-Amplified Detection of Mn²⁺

Abstract

Portable detection of highly toxic environmental pollutants has been recognized as the most efficient method, but it still faces challenges. Here, a new photothermal signal-amplified sensing platform based on a carbon dot (CD) photosensitizer anchored in porous wood was fabricated for ultrasensitive determination of Mn 2+ using a thermometer as the signal output. The resulting CDs@wood photosensitization structure could inhibit the aggregation-induced quenching of CDs, thereby greatly improving the efficiency of singlet oxygen ( 1 O 2 ) production. The experiment result showed that the CDs@wood photosensitizer could generate threefold higher 1 O 2 generation efficiency than CDs alone upon the same light irradiation. High 1 O 2 generation efficiency improves the yield of oxidizing Mn(II) to Mn(III) at neutral pH, thereby drastically enhancing the capability of Mn(III) to oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) and improving photothermal signal generation under 660 nm irradiation. The above photothermal signal changes can be easily captured by the portable thermometer. However, other divalent metal ions do not have this effect; thus, Mn(II) as low as 44.6 nM can be selectively detected. Our work highlights a strategy to design highly efficient oxygen photosensitizers by tailoring space distribution of CDs for portable and highly sensitive detection and other applications.

A Review on Hydrogels with Photothermal Effect in Wound Healing and Bone Tissue Engineering

“…Hydrogels with a porous network have been used widely in biomedicine. One of the strategies to solve aggregation is that nanomaterials can be dispersed effectively in hydrogels [ 62 , 63 ]. In addition, nanomaterials can be surface-modified and covalently cross-linked or non-covalently cross-linked with hydrogels [ 64 , 65 ].…”

Singlet Oxygen Photosensitization Using Graphene-Based Structures and Immobilized Dyes: A Review

“…Carbon dots (CDs) − and graphene quantum dots (GQDs) , have received widespread interest in photocatalysis, PTT, PDT, and bioimaging due to their desirable photocatalytic, thermal, optical, and biocompatible properties. − Potential applications of CDs and GQDs in bioimaging, PTT, and type I PDT are mainly discussed in recent review papers. , For example, functionalized GQDs with monosaccharide sugar were used as bioimaging agents to determine the trafficking as well as overall distribution of the cell surface carbohydrate receptor . CDs were also used for the enhanced and selective PTT of cancer cells .…”

Innovations in the Solid‐State Fluorescence of Carbon Dots: Strategies, Optical Manipulations, and Applications

“…Some natural polymers such as cellulose [ 104–108 ] and starch [ 109–114 ] can also be used as solid‐state substrates to support SSF. Zhang et al.…”