Bidirectional PET in selective detection of Nb(V) by synergistic modification of carboxyl groups and carbon vacancies in N-CQDs. - Fu, Ce; Kong, Lingxin; Shan, Ao; Zhang, Yanan; Zhai, Zhaoxia; Qiu, Peilun; Hu, Chuqiao; Liu, Jianqiao; Wang, Junsheng (Applied Surface Science, 2026)