▎ 摘　　要

NOVELTY - A pinewood-based graphene quantum dot is prepared by using pinewood as raw material, hydrothermally carbonizing to prepare pine-based graphene quantum dot solution, centrifuging and dialyzing to separate and purify graphene quantum dots, and freeze-drying solid powder. USE - The pinewood-based graphene quantum dot is used in water heavy metal detection for detecting iron (III) ion concentration in water and cell fluorescence probes (all claimed). ADVANTAGE - The product has simple preparation method, good luminescence stability and high biocompatibility. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparation of the pinewood-based graphene quantum dot comprising using pinewood as raw material, grinding into solid pinewood powder, passing through 200-800 mesh sieve, moving to hydrothermal reaction kettle, adding ultrapure water, mixing, heating, holding, performing ice water bath on reaction kettle to stop hydrothermal reaction to obtain pinewood solid-liquid mixture, removing pinewood coarse residue to get supernatant, separating and purifying supernatant by centrifugation to obtain pinewood-based graphene quantum dot solution, dialyzing and separating using dialysis bag, periodically replacing dialysate for 6-12 hours, and freeze-drying; (2) use of pinewood-based graphene quantum dot to detect iron (III) ion concentration in water comprising formulating pinewood-based graphene quantum dot solid powder to pinewood-based graphene quantum dot aqueous solution, mixing with water sample, reacting at room temperature for 15 minutes, detecting fluorescence intensity value at excitation wavelength of 330 nm, and calculating concentration of iron (III) ion in water sample to be tested; and (3) use of pinewood-based graphene quantum dot to cell fluorescence probes comprising formulating pinewood-based graphene quantum dot solid powder to pinewood-based graphene quantum dot aqueous solution, filtering using 0.22 mu m sterilizing filter film, using HeLa cells as observation object, placing filtered pinewood-based graphene quantum dot aqueous solution and HeLa cells in high glucose culture medium, culturing in constant temperature culture box with 5% carbon dioxide for 24 hours, washing with pre-heated phosphate buffer solution, observing HeLa cells under laser confocal microscope, absorbing pinewood-based graphene quantum dots by cells, receiving excitation wave, emitting fluorescence, and revealing cell structure.