Glutathione-facilitated design and fabrication of gold nanoparticle-based logic gates and keypad lock

Abstract

In this paper, we describe how we developed a simple design and fabrication method for logic gates and a device by using a commercially available tripeptide, namely glutathione (GSH), together with metal ions and disodium ethylenediaminetetraacetate (EDTA) to control the dispersion and aggregation of gold nanoparticles (NPs). With the fast adsorption of GSH on gold NPs and the strong coordination of GSH with metal ions, the addition of GSH and Pb(2+) ions immediately resulted in the aggregation of gold NPs, giving rise to an AND function. Either Pb(2+) or Ba(2+) ions induced the aggregation of gold NPs in the presence of GSH, supporting an OR gate. Based on the fact that EDTA has a strong capacity to bind metal ions, thus preventing the aggregation of gold NPs, an INHIBIT gate was also fabricated. More interestingly, we found that the addition sequence of GSH and Hg(2+) ions influenced the aggregation of gold NPs in a controlled manner, which was used to design a sequential logic gate and a three-input keypad lock for potential use in information security. The GSH strategy addresses concerns of low cost, simple fabrication, versatile design and easy operation, and offers a promising platform for the development of functional logic systems.

Gold Nanoparticle-Based Facile Detection of Human Serum Albumin and Its Application as an INHIBIT Logic Gate

“…The A 650 /A 520 is documented to be related to the aggregated and dispersed Au NPs and thus the degree of aggregation of Au NPs. 21,24 As shown in Figure 2B, in the absence of HSA, the value of A 650 /A 520 immediately increased to 1.4 by the addition of melamine, indicating the rapidly extensive aggregation of the Au NPs induced by melamine. Increase of the value of A 650 /A 520 became much slower when the Au NPs were incubated with HSA for 30 s or longer time.…”

“…24 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 5…”

“…Au NPs have been recognized as ideal candidates for fabrication of colorimetric logic gates which can transduce specific chemical/biological inputs into optical outputs. [21][22][23][24] Here, by using HSA and melamine as inputs and the color changes of Au NPs as outputs, an INHIBIT logic gate which may be potential useful in point-of-care medical diagnosis is developed based on the anti-aggregation effect. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Experimental Section…”

User Authorization at the Molecular Scale

“…The latter are macroscopic analytical devices that, similar to the way the olfactory system operates, can interact non‐specifically with a wide range of analytes and discriminate among them by creating a wide range of unique identification patterns . Hence, the main difference between 8 and the molecular keypad locks discussed before is that instead of generating a single digital output (0 or 1) for each code entry, it associates each password with a unique emission “signature” that enables it to authorize multiple users.…”

Label-free colorimetric logic gates based on free gold nanoparticles and the coordination strategy between cytosine and silver ions

“…[1][2][3] Over the past few decades, considerable efforts have been dedicated to replicating the Boolean logic gates on a molecular scale via various materials, such as organic molecules, proteins, nucleic acids, enzymes, and supramolecular hydrogels [4][5][6][7][8][9] that display a variety of logic outputs (e.g., AND, OR, XOR, etc.) [11][12][13][14][15][16] As a result, AuNPs represent an ideal platform to translate molecular events into logic systems with a large impact on the color properties of the solution, allowing to replicate Boolean logic gates on a molecular scale. 10 However, most of these logic gates employed fluorescence signals as their outputs, which were often limited by complex handling procedures and a lack of portability.…”