Abstract: The method for preparing theragnostic carbon quantum dot nanomedicine composition comprises collecting and processing fresh plant samples of Azadirachta indica; mixing 50 g of crushed dried neem leaves powder with 500 mL of methanol and left to extract for 1 week; filtering the mixture and condensing using a rotary evaporator, and lyophilizing to obtain the extract; dissolving 0.57 g L-cysteine in 10 mL of deionized water and mixing with 1.5 g of citric acid to form a solution; ultrasonicating the solution for 10 minutes and then heating in a microwave oven for 4 minutes; cooling the solution to room temperature and then dissolving in 10 mL of deionized water to obtain a brown solution; centrifuging the brown solution at 9000 rpm for 10 minutes to remove impurities and filtering with a filter; and extracting the Carbon quantum dot (CQD) solution with ethyl acetate and storing in a refrigerator at 4° C.

Abstract: A thin film coating apparatus is disclosed, including a sample holder rotatably configured in the apparatus. The sample holder is coupled to a motor configured to rotate the sample holder. The apparatus includes a heating chamber disposed around the sample holder. The heating chamber is configured to supply heat to a substrate loaded on the sample holder. The apparatus includes a top cover configured to selectively allow access to the substrate loaded on the sample holder. A controller is configured to: detect a speed of rotation of the sample holder; and operate the top cover to allow access to the substrate loaded on the sample holder when the detected speed of rotation of the sample holder is within a predefined range.