초록
<▼1><P>In this study, new nitrogen-doped carbon dots (N-CDs) were prepared by utilizing rambutan seed waste and <SMALL>L</SMALL>-aspartic acid as dual precursors (carbon and nitrogen sources) through a hydrothermal treatment method. The N-CDs showed blue emission in solution under UV light irradiation. Their optical and physicochemical properties were examined <I>via</I> UV-vis, TEM, FTIR spectroscopy, SEM, DSC, DTA, TGA, XRD, XPS, Raman spectroscopy, and zeta potential analyses. They showed a strong emission peak at 435 nm and excitation-dependent emission behavior with strong electronic transitions of C <svg xmlns='http://www.w3.org/2000/svg' version='1.0' width='13.200000pt' height='16.000000pt' viewBox='0 0 13.200000 16.000000' preserveAspectRatio='xMidYMid meet'><metadata> Created by potrace 1.16, written by Peter Selinger 2001-2019 </metadata><g transform='translate(1.000000,15.000000) scale(0.017500,-0.017500)' fill='currentColor' stroke='none'><path d='M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z'/></g></svg> C/CO bonds. The N-CDs exhibited high water dispersibility and great optical properties in response to some environmental conditions such as heating temperature, light irradiation, ionic strength, and storage time. They have an average size of 3.07 nm and good thermal stability. Owing to their great properties, they have been used as a fluorescent sensor for Congo red dye. The N-CDs selectively and sensitively detected Congo red dye with a detection limit of 0.035 μM. Moreover, the N-CDs were utilized to detect Congo red in tap and lake water samples. Thus, rambutan seed waste was successfully converted into N-CDs and these functional nanomaterials are promising for use in important applications.</P></▼1><▼2><P>In this study, new nitrogen-doped carbon dots (N-CDs) were prepared by utilizing rambutan seed waste and <SMALL>L</SMALL>-aspartic acid as dual precursors (carbon and nitrogen sources) through a hydrothermal treatment method and applied as a fluorescent sensor toward Congo red.</P></▼2>