The invention provides a construction method of a microbial sensor and an application method of a microbial sensor. The construction method comprises the steps of: the step 1, constructing an
amino acid defective strain to be detected; the step 2, intercepting
target gene fragments required by an LuxI / LuxR circulating amplification line for connection to obtain a
plasmid comprising the circulatingamplification line based on an LuxI / LuxR
system, and transforming the recombinant
plasmid into an
amino acid defective strain to ensure that the report
gene fragments are repeatedly expressed; and the step 3, culturing the strain to a
logarithmic growth phase, and performing starvation culture in a culture medium. According to the invention, the
amino acid defective strain to be detected is circularly amplified and is used as a microbial sensor, the
nucleic acid aptamer combined with the
protein marker and having high specificity and high affinity with a
protein marker is used as a 'bridge',the detection of the
protein marker is converted into the detection of the amino acid to be detected, the constructed microbial sensor is used for achieving the detection of the macromolecular biomarker, and a circular amplification
system is combined as a
signal amplification means so that the sensitivity of quantitative detection is greatly improved.