Carbon dots (CDs) areone of the green nano-fluorescent agents. Suspension of CDs can show good fluorescence performance. However, aggregation-induced quenching effects in solid-state CDs can lead to the disappearance of the fluorescence properties of CDs powder, which limits their practicability. In this work, CDs are obtained by doping other elements in CDs to change fluorescent wavelength and color to improve the contrast between the LFPs and the substrate backgrounds. Another improvement is the good dispersion of CDs on the surface of low-cost hydrotalcite for avoiding the occurrence of fluorescence quenching. Herein, Gd/N-doped CDs (Gd/N-CDs) are obtained using tartaric acid as carbon source, triethylenetetramine as nitrogen source, and GdCl3 by hydrothermal method, and then green emissive nanocomposite has been synthesized by depositing the Gd/N-doped carbon dots into hydrotalcite (Gd/N-CDs@H) via hydrothermal process for the recognition of LFPs. The good dispersion of the nano-sized Gd/N-CDs on the surface of hydrotalcite overcomes the fluorescence quenching of the Gd/N-CDs in the solid-state and can enhance the solid-state fluorescence. The Gd/N-CDs@H emits stable, strong green fluorescence and exhibits vivid images of LFPs on various substrates such as glass slides, copper foil, tiles, plastic, aluminum foil and paper. The high-level details of ridge patterns of fresh and aged LFPs can be clearly identified with good clarity and high contrast without background interferences under an excitation of 450 nm light source.