Nitromethane

Praziquantel (PZQ, (11bRS)-2-(Cyclohexylcarbonyl)-1,2,3,6,7,11b-hexahydro-4-H-pyrazino[2,1-a]isoquinolin-4-one)) was of Ph. Eur. grade and kindly donated by Fatro S.p.a. (Bologna, Italy). Nitromethane, acetonitrile, 1,4-dioxane, ethyl acetate, ethanol, methanol, 2-pyrrolidone and acetic acid of reagent grade were from SIGMA-Aldrich (Milano, Italy). The HiPersolv Chromanorm methanol used for the HPLC analysis was purchased from VWR Chemicals (BHD PROLABO, Milano, Italy).

The synthesis of AuCl₃ dopant is according to the previous reports^{40 (link)–42 (link)}. Briefly, 30 mg gold chloride (AuCl₃) powders (≥99.99 %, Sigma Aldrich) were dissolved in the 5 ml nitromethane (≥95 %, Sigma Aldrich), then the solutions (20 mM) were sonicated for 3 h at 60 degrees followed by filtration to filter the large Au aggregates. The 20 mM AuCl₃ solutions were then diluted with different concentration (10 mM and 5 mM). Note that all operations were performed in glove box to protect the reagents from the air environment. About 3–5 drops of 5 mM AuCl₃ solutions were dropped on the SiO₂/Si substrate with MoS₂ devices on top and spin-coated at 3000 rpm for 1 min, then baked on the hotplate at 100 °C for 5 min.

Key steps in the fabrication of the device are overviewed in Figure 2b. The key fabrication steps were as follows: i) the stretchable electrode was mounted under tension on a thin optical glass substrate (24 mm x 60 mm, #0‐thickness cover glass, Gold Seal) with 250 µm‐thick double‐sided acrylic tape (3M), and a drop (≈0.5–2 µL) of liquid acrylic photoresist (IP‐Dip, Nanoscribe, GmbH) was deposited over and beneath the recording array; ii) the glass and sample were inverted and the microclip cap (Figure 2c) printed through the optical glass substrate using a two‐photon‐polymerization‐based, dip‐in resonant direct laser writing (rDWL) process;^[79] iii) the glass substrate and sample were righted, and the base of the microclip was printed with the rDWL process; iv) the photoresist was developed and tape adhesive dissolved by submerging the glass substrate, electrode, and nanoclip in nitromethane (Sigma Aldrich) for 20 min, and the whole device rinsed in methoxy‐nonafluorobutane (Novec 7100; 3M) to remove trace solvent residue; v) the assembly was removed from the glass slide and compression bonded to a connectorized PCB as described above. All mechanical design was performed with Solidworks (Dassault Systèmes). All tested and imaged devices were fabricated using a custom rDLW system.^[79]

The single-crystal samples were synthesized on the basis of our previously published method (35 (link)). For MAPbBr₃, the precursor solution (0.45 M) was prepared by dissolving equal molar ratio of MABr (Dyesol, 98%) and PbBr₂ (Sigma-Aldrich, ≥98%) in dimethylformamide (DMF; Sigma-Aldrich, anhydrous 99.8%). After filtration, the crystal was allowed to grow using a mixture of dichloromethane (Sigma-Aldrich, ≥99.5%) and nitromethane (Sigma-Aldrich, ≥96%) as the antisolvent (41 (link)). Similar method was used for CsPbBr₃ crystal growth (42 ). The precursor solution (0.38 M) was formed by dissolving equal molar ratio of CsBr (Sigma-Aldrich, 99.999%) and PbBr₂ in dimethyl sulfoxide (DMSO; EMD Millipore Co., anhydrous ≥99.8%). The solution was titrated by methanol until yellow precipitates show up and did not redissolve after stirring at 50°C for a few hours. The yellow supernatant was filtered and used for the antisolvent growth. Methanol was used for the slow vapor diffusion. All solid reactants were dehydrated in a vacuum oven at 150°C overnight, and all solvents were used without further purification.