Dermal tattoo biosensors for colorimetric metabolite detection. - Yetisen, AK; Moreddu, R; Seifi, S; Jiang, N; Vega, K; Dong, X; Dong, J; Butt, H; Jakobi, M; Elsner, M; Koch, AW (Angewandte Chemie International Edition, 2019)