Carbon dot-based inverse opal hydrogels with photoluminescence: dual-mode sensing of solvents and metal ions

Abstract

Carbon dot-based inverse opal hydrogels (CD-IOHs) with photoluminescence are created and dual-mode detection of solvents and metal ions is demonstrated.

Bottom-Up Assembled Photonic Crystals for Structure-Enabled Label-Free Sensing

“…The hydrogel-based PhCs can serve as excellent platforms due to the ease of modification by other functional materials ( i.e. , DNA molecules, 38 carboxylic groups, 89 thiol functional groups, 94 polyelectrolytes, 49 CDs, 90 and enzymes 50 ) in order to endow specific recognition capabilities when exposed to the target analytes, resulting in a volume change and optical response. One of examples is the hydrogel suspension array for multiplexed label-free DNA detection that was developed by Gu’s group, 38 which integrates both bioresponsive hydrogel SPCs and QD-encoded technology.…”

“…For example, inverse opal hydrogels infiltrated with CDs have been designed as a dual-mode sensing platform for selective detection of metal ions. 90 This design has the advantage of a simple fabrication procedure without probe molecule preimmobilization prior to target detection, compared to the above-discussed works. Variation in the lattice spacing of the inverse opal hydrogels induced by metal ions leads to a Bragg diffraction peak shift in the reflection mode and a fluorescence signal change in fluorescence mode.…”

“…Another strategy for lattice-spacing-induced sensing is to utilize hydrogel-based PhC structures. The hydrogel-based PhCs can serve as excellent platforms due to the ease of modification by other functional materials (i.e., DNA molecules, 38 carboxylic groups, 89 thiol functional groups, 94 polyelectrolytes, 49 CDs, 90 and enzymes 50 ) in order to endow specific recognition capabilities when exposed to the target analytes, resulting in a volume change and optical response.…”

“…Mechanically induced changes of lattice spacing or volume of PhC structures can cause a significant shift of the Bragg diffraction peaks according to the Bragg–Snell law. These changes can be caused by changes in charge or osmotic pressure in the PhC in response to analyte binding of such as heavy metals, , proteins, kinase, and nucleic acids, have been demonstrated. The lattice spacing or volume change generally occurs in hydrogel-based PhC structures with non-close-packed periodicity and is driven by the total free energy of the system.…”

“…The strategy of dual-mode sensing has also been employed. For example, inverse opal hydrogels infiltrated with CDs have been designed as a dual-mode sensing platform for selective detection of metal ions . This design has the advantage of a simple fabrication procedure without probe molecule preimmobilization prior to target detection, compared to the above-discussed works.…”