"I thought molecular computers might be able to solve problems that aren't currently solvable with electronic computers; I wanted the argument to be convincing."Adleman limited his "test" to seven cities connected by fourteen possible routes.
Moreover, we fabricate an inspiring and useful biosensor with RGB colorful results based on the DU-IFE (a DNA caliper), providing a vivid prototype for potential biological applications.
It's a hundred times faster than the best serial supercomputer. It's a trillion times denser than the best storage media.
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But Adleman wanted to tackle the question from the opposite direction.
What if life itself, already susceptible to genetic engineering, could be used to solve problems?Since not all cities are directly connected, the challenge lay in discovering the one continuous path to link them all.A Hamiltonian path problem involving four or five cities can be solved by doodling on a piece of paper, but when the number of cities grows by even a small amount, the problem's difficulty balloons - it becomes what is known in mathematical terms as "hard." Hard problems cannot be solved efficiently by algebraic equations.Answers can only be found by crunching through every possible solution, and most hard problems are too difficult for humans or computers to solve.Finding a Hamiltonian path connecting 100 cities using a well-known algorithm, for example, would take 10147 operations.Using what is essentially a four-letter alphabet, DNA stores information that is manipulated by living organisms in almost exactly the same way computers work their way through strings of 1s and 0s. If the answer's yes, new ways of building entirely different kinds of computers would open up - computers so fast they could solve some of today's unsolvable problems, so small they would exist at the molecular level.Thanks to learning algorithms and other evolutionary tools being incorporated into computers, the machines around us are becoming more lifelike.DNA computing has shown impressive developments and exhibited amazing power over the past few decades.However, most current DNA logic devices can only produce single-modal output that is monochromic or even invisible, which greatly limits their reliability and practicality, integration capability and computing complexity.Emission-tunable upconversion nanoparticles (UCNPs) are ideal multicolor outputs for DNA computing, however UC luminescent (UCL) DNA logic systems have rarely been reported.Here, for the first time, we report “DNA-Unlocked Inner-Filter-Effect” (DU-IFE) between oxidized 3,3′,5,5′-tetramethylbenzidine (Ox TMB) and upconversion nanoparticles (UCNPs) that subtly matches a “lock–key” strategy.