Method for simultaneous instrument-free quantitative detection of Hg < 2 + >, Cu < 2 + > and Ag < + > based on three-dimensional paper chip

The invention discloses a simultaneous instrument-free quantitative detection method for Hg < 2 + >, Cu < 2 + > and Ag < + > based on a three-dimensional paper chip. Hg < 2 + >, Cu < 2 + > and Ag < + > respectively react with o-phenylenediamine to generate a metal nano-cluster product, and the metal nano-cluster product is used for blocking pore channels of the nano-porous membrane so as to selectively change the wettability of the paper chip, so that the flowing length of the color indicator in the paper chip is regulated and controlled. And the concentrations of Hg < 2 + >, Cu < 2 + > and Ag < + > are inversely proportional to the flow length of the color indicator in the paper chip. Instrument-free simultaneous quantitative analysis of Hg < 2 + >, Cu < 2 + > and Ag < + > can be realized by using the flow length of the color indicator in the ruler paper chip. The method disclosed by the invention has the outstanding advantages of simplicity in operation, low cost, rapidness in analysis, no need of professio