Most PSs are hydrophobic and aggregate in aqueous solutions, affecting their photochemical and photobiological properties.106,110 For this reason, Lim et al. have proposed a promising approach for photodynamic inactivation of viruses with NPs, developing sodium yttrium fluoride (NaYF4) upconversion NPs (UCNs) with zinc phthalocyanine PSs grafted onto their surfaces. Unlike most PSs, these UCNs are coated with polyethylenimine (PEI), which render them hydrophilic and easier to manipulate. These UCNs showed antiviral activity against Dengue virus serotype 2 and adenovirus type 5, which were used as models of enveloped and non-enveloped viruses, respectively.110 MXenes111,112 are a large family of 2D transition metal carbides, nitrides,113 and carbonitrides114 that exhibit unique electronic, optical, and catalytic properties. They have the general formula Mn+1XnTx, where M is an early transition metal (Ti, Zr, V, Mo, etc.), X is C and/or N, Tx represents the surface functional groups (=O, −OH, −F, −Cl), and n = 1–4.115,116 Some examples include Ti3C2Tx, V2CTx, and Nb2CTx, with over 30 stoichiometric compositions already synthesized with more than 100 predicted. Biocompatible MXenes, such as Ti3C2Tx, are hydrophilic and are among the most efficient light-to-heat transforming materials.117 The plasmon resonance extinction maxima of Ti3C2Tx is at 780 nm, enabling the use of near-infrared (IR) light for PDT. Several other MXenes have absorption maxima in the IR range and have shown outstanding performance in PDT and theranostic applications.118