Sensitive and Rapid Extraction-Free Detection of Furfural in Mineral and Natural Ester Oils by 4-ATP Modified SERS Substrate. - Fu Wan; Yu Lei; Mingliang Wang; Shufan Li; Ruiqi Liu; Yaoyang Xia; Changding Wang; Hongfei Liu; Weigen Chen (IEEE Trans. Instrum. Meas., 2025)