  Using the coincidence-count (CC) measurement of the generated
frequency-entangled twin-photons beam (TWB) via the process of type-I
spontaneous parametric-down conversion (SPDC) in BBO nonlinear crystal (NLC),
we have precisely measured the transmittance of very diluted Rabbit- and
Human-DNA, Methylene-Blue (MB), as a disinfectant, and thin-film multilayer at
near IR wavelength 810nm with an accuracy in order of $\% 0.01 $ due to the
quantum correlation, while accuracy of classical-like measurement, single-count
(SC), is in order of $\% 0.1 $ in our setup. Moreover, using quantum
measurement of the transmittance, the different types of DNA with the same
concentration, and also very diluted (in order of pg/$ \mu $l) different
concentrations of DNA and MB solutions are distinguished and detected with
high-reliability. Interestingly, in case of Human-DNA samples in contrast to
our classical-like measurement we could precisely detect and distinguish two
very diluted concentrations $ 0.01\rm ng/\mu l $ and $ 0.1\rm ng/\mu l $ with
high reliability while commercial standard spectrometer device of our
DNA-manufacturer never could detect and distinguish them. Surprisingly,
measurement on the thin-film multilayer illustrates that the introduced method
in this work might be performed to cancer/brain tissues or Stem cells for
cancer therapy, and may hopefully open a pave and platform for non-invasive
quantum diagnosis in future.
